Tx Frequency Research Articles

Abstract 1177: The chronology of immune-related adverse events (irAEs)-mechanistic implications

Abstract Immune Oncology (IO) is a novel component of the oncology armamentarium given its distinct mechanism of action, and by extension, unique mechanisms of toxicity (Tx). To recognize these unusual Txs, the term irAEs was popularized in clinical trials. Most organs have been involved by irAEs and autoimmunity has been implicated commonly by practicing oncologists. The onset of irAEs has not been studied well, however. We reasoned that autoimmune phenomena would be expected early after IO, since this is the timeframe within which T-cells expand to exert their effects on tumor and other ‘self’ tissues. It follows that if autoimmunity is the sole mechanism of irAEs, such toxicities should be reported early. Mechanism(s) of irARs may prove important for IO duration discussions. In some cases, tumor antigenic epitopes may mimic self-tissues, and in such cases irAEs develop early after initiation of IO. We hypothesized that irAEs have distinct chronology: earlier events representing autoimmunity (unavoidable); later events reflecting an intercurrent exposure to an antigen (e.g., virus) and therefore are avoidable by limiting duration of IO. Methods: We reviewed published IO monotherapy trials if individual patient data (swimmers’ plot) were reported. We derived the timing and frequency of Tx. We used therapy discontinuation without progressive disease as a surrogate for Tx if reported before the planned 24 months IO therapy.Results: Table depicts the data on included clinical trialsConclusion: The emergence of irAEs after IO extends over a protracted periods with 86% of events occurring beyond 4 months of IO. Though responses occasionally develop late after IO, for Tx consideration, T-cell expansion starts within days of IO initiation, and if autoimmunity is the mediator of Tx, irAEs would emerge only early. Our results suggest dual mechanisms and provide one more impetus to consider shortening IO duration. Tumor Author Discontinued IO (n) Months of IO Discontinuation 0-2 3-4 5-6 7-8 9-10 11-12 13-14 15-16 17-18 19-20 21-22 NSCLC Topalian 12 1 1 4 1 1 3 1 Dart 11 3 4 3 1 Warburton 56 2 2 7 8 7 22 1 3 1 2 1 Melanoma Topalian 13 4 1 2 1 2 2 1 Weber 2 1 1 Demetriou 66 8 4 6 5 6 10 6 10 6 5 RCC Topalian 3 1 2 Total 163 14 10 15 25 14 38 9 15 10 11 2 8% 6% 9% 15% 8% 23% 5% 9% 6% 7% 1% Citation Format: Farah Mazahreh, Haya Safar, Liyan Mazahreh, A. Mazin Safar. The chronology of immune-related adverse events (irAEs)-mechanistic implications [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1177.

A Compact Low-Loss High-Selectivity Excellent-Isolation FBAR Duplexer Integrated Chip for LTE Band-3 Industrial Applications

This brief presents a complete design flow for a compact low-loss high-selectivity excellent-isolation LTE Band3 (B3) duplexer (TX: 1710 MHz-1785 MHz, RX: 1805 MHz-1880 MHz). The proposed chip duplexer is based on the thin film bulk acoustic resonator (FBAR). In addition to the general design method, the effects of temperature drift, resonator performance distribution on wafer, the quality factor of inductance, device yield, and dissipated power density distribution on the design flow are described. These aspects are of great significance for the batch production of FBAR duplexers in the industry. Samples that pass the above industrial process are selected for testing. Measured results show reasonable consistency with the co-simulation results. 1.2/1.0-dB minimum IL in TX /RX band, 20-dB rejection in 3.5 GHz (second harmonic of TX), and more than 50 dB isolation in both TX and RX frequency are achieved with less massload simultaneously.

Single Waveguide Feed Omnidirectional and Circularly Polarized Transceiver Waveguide Slot Antenna for Satellite Communication Applications

In this study, an omnidirectional and circularly polarized transceiver antenna, which can be used in simultaneous operations over transmit (TX) and receive (RX) channels for telemetry, tracking, and command (TTC) applications on the space segment of satellite communication, is proposed. The radiation and feed parts of the antenna consist of waveguide structures for high power necessity in transmit (telemetry) section. The radiation part includes two different sections of rotationally symmetric slotted arrays on circular waveguide, and radially outward metallic disks to improve omnidirectionality and circular polarization. The feed part contains a dual-band mod converter from rectangular TE10 mode to circular TM01 mode for symmetric field excitation over slots where the input of the converter is the standard rectangular waveguide. The design, simulation, and measurement results of the antenna are shown over a 3D printed prototype at Ku-band with center frequencies of 12 GHz and 14.25 GHz for TX and RX, respectively. With thin slots in telemetry section and thick slots in telecommand section, measured bandwidths for TX and RX frequencies are obtained approximately as 200 and 450 MHz, respectively. While TX band with maximum 3 dB gain variation over azimuth, maximum 3 dB axial ratio and minimum −3 dBi gain over 70° elevation beamwidth has relatively better performances at the expense of narrow bandwidth, RX band has maximum 3.5 dB gain variation over azimuth, maximum 4 dB axial ratio and minimum −6 dBi gain over 55° elevation beamwidth at the expense of wide bandwidth.

Realization of In-Band Full-Duplex Operation at 300 and 4.2 K Using Bilateral Single-Sideband Frequency Conversion

CMOS-integrated in-band full-duplex (IBFD) operation in wireless links and cryogenic quantum platforms was previously enabled by magnetic-free circulators using the phase non-reciprocity from spatial-temporal modulation. In this article, we present an alternative and simple integrated circuit scheme, which not only realizes non-reciprocal signal flows required for IBFD operations but also improves the isolation performance by completely eliminating any chip-level transmit (TX)-to-receive (RX) coupling. The above functions are enabled by performing a direction/frequency-independent, single-sideband down-conversion to the counter-propagating TX and RX signals, which creates opposite deviations of on-chip TX and RX frequencies with respect to the antenna (ANT) frequency. Such a principle also broadens the isolation bandwidth and enables integrated receiver down-mixing function. As a proof-of-concept, a 3.4-4.6-GHz (30% fractional bandwidth) IBFD interface is implemented using a 65-nm bulk CMOS technology. The measured TX-to-RX isolation of the circuit is 32-51 dB at 300 K, and 14-29 dB at 4.2 K. The measured TX-to-ANT and ANT-to-RX insertion losses are 3.0 and 3.2 dB at 300 K, and 1.9 and 2.0 dB at 4.2 K. At 300 K, the measured TX-to-ANT and ANT-to-RX IIP3 are 29.5 and 27.6 dBm, respectively. The IBFD core of the chip occupies an area of 0.27 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and has a dc power (nominally consumed in an on-chip modulation clock generator) of 48 mW at 300 K and 42.6 mW at 4.2 K.

Harmonic Reflection Amplifier for Widespread Backscatter Internet-of-Things

The highly power-efficient backscattering communication scheme holds solid potentials to lead the Internet of Things technologies. However, the asymmetric radio frontend architectures that ensure cheap and pervasive communicating things and tags at one end of the link, overburden the other end of the link (“reader”) with complicated and expensive hardware. This turns out to prevent the integration of the technology in the wide spectrum of consumer electronic devices (e.g. RF smartphone platforms). By separating TX and RX frequency bands, the harmonic backscattering scheme drastically loosens the technological constraints toward integration. We propose here the use of a single tunnel diode to build a harmonic reflection amplifier (HRA), using the nonlinear behavior of the negative differential resistance region to both generate harmonics and amplify the signals. The circuit also behaves like a common backscatter, with the same-frequency backscattering modulation for operation with legacy readers. Operating below 150 mV, the HRA drains 144-μW dc power with a measured positive conversion gain of 18 dB.

Extreme temperatures linked to the atmospheric blocking events in Turkey between 1977 and 2016

Extreme maximum (Tx) and extreme minimum temperature (Tn) frequency distributions during summer and winter for blocked conditions were analyzed within Turkey during the period from 1977 to 2016 by using observational data. The Tx (0.5–0.8%) and Tn (0.4–2.0%) frequencies vary between these values for the entire period during summer. However, Tx varies between 0.0 and 1.0, while Tn varies between 0.8 and 2.4 during winter. It is quite clear that atmospheric blocking has a greater cooling effect during winter. The maximum values for Tx and Tn are observed when the block center located within the easternmost sector impacting Turkey for summer. The maximum Tx frequency is observed in association with blocking in the westernmost sector, and the maximum Tn frequency is observed with blocking in the easternmost sector impacting Turkey during the winter season. Block intensity has almost no impact on Tx frequency although it has enhancing effect on Tn frequency during the summer. For winter, block intensity has a decreasing effect on both the maximum Tn and maximum Tx. The maximum Tx and Tn values increase with the block size for the summer. During the winter, the maximum Tx frequency decreases with the increase in the size of a blocking event; however, the greatest Tn frequency is observed within the 0°–30° E sector and lowest within the 30° E–60° E sector. The block duration has an enhancing influence on the maximum Tx value, while maximum Tn is observed during short-duration events and a minimum is observed during moderate-duration events during the summer season. For the winter season, the block duration has a decreasing effect for Tx frequencies and increasing effect for Tn.

First-line drug selection versus sequential treatment in advanced pancreatic cancer: Does it really matter? Multi-institutional Canadian perspective.

673 Background: Folfirinox (FFX) and Gemcitabine with nab-Paclitaxel (GN) are both proven to be superior to Gemcitabine (G) in the first line treatment (1LTx) for advanced pancreatic cancer (APC). Yet, the optimal 1LTx selection nor sequential Tx (ST) has not been fully established. Therefore, the best choice for 1LTx is a matter of debate often influenced by access to drugs. This analysis was conducted to compare outcomes based on 1Ltx selection and ST in APC. Methods: We assessed patients (pts) with APC who received either FFX or GN as 1LTx during 2010-2019 at three Canadian institutions. As well as the ST used. The main objective was to assess survival. Kaplan method and log-rank test were used for survival curves. Results: This retrospective study included 231 pts; 1LTx included 143 pts on FFX and 88 pts on GN. FFX pts were predominantly male; 89(62.2%) vs 46(52.3%) and slightly younger (median age 62 vs 66) than GN. WHO performance status (PS) of 0 were 38 (28.4%) vs 14 (16.5%) and 1 were 90 (67.2%) vs 65 (76.5%) respectively. There were more grade 3-4 toxicity in FFX vs GN group: GI 55 (38.5%) vs 15 (17%) and hematologic 51 (35.4%) vs 20 (22.7%) respectively. Grade 3-4 neutropenia rates were similar in both regimens. The median PFS of FFX was 5.5 months (95% CI: 5.0-6.7) vs 5.1 (95% CI: 3.8-7.1) with GN (p=0.37). The median OS with FFX was 9.3 months (95% CI: 7.5-11.1) vs 10.2 (95% CI: 6.8-11.3) with GN (p=0.81). There were not statically significant. Table shows Tx frequency across 4LTx. 2LTx and beyond regimens included G, GN, FFX, Capecitabine, Irinotecan liposome plus 5-FU, Irinotecan and clinical trials. Conclusions: Our results revealed that pts who received 1LTx FFX or GN had similar PFS and OS even though 1LTx FFX group was younger with better PS, allowing to continue 2-4LTx more frequently when compare with 1LTx GN group. Therefore, 1LTx selection appear to have more impact in our pts rather than ST, whereas GN is less toxic and seems a preferable 1LTx choice for most pts. FFX could be reserved for young high-performance pts. [Table: see text]

A SAW-Less Tunable RF Front End for FDD and IBFD Combining an Electrical-Balance Duplexer and a Switched-&lt;italic&gt;LC&lt;/italic&gt; N-Path LNA

This paper proposes a surface-acoustic wave (SAW)-less tunable RF front end (RF-FE) using an electrical-balance duplexer (EBD) integrated with a switched-LC N-path low-noise amplifier (LNA). The EBD cancels the transmitter–receiver (TX–RX) leakage at the RX frequency by dynamically optimizing the balance of a hybrid transformer, which enables in-band full-duplex (IBFD) operation. A transconductor-based LNA in parallel with a switched-LC N-path network creates input and output notches to reject TX leakage for frequency-division duplexing (FDD) operation. The LNA’s signal-handling capability is enhanced via optimum switch biasing. Fabricated in 0.18- $\mu \text{m}$ SOI CMOS, the RF-FE offers >50-dB tunable rejection from the TX port to LNA output at both TX and RX frequencies, for all 3GPP bands from 0.7 to 1 GHz (i.e., FDD case). It is the first tunable RF-FE including an LNA that achieves +70-dBm TX-path IIP3, and +30-dBm in-band TX power while cancelling the self-interference by >50 dB (i.e., IBFD case). The RF-FE consumes 62.5 mW at 1 GHz with 11.7-dB RX cascaded NF, 3.6-dB TX insertion loss, and 9.62 mm2 active area.

A SNR-Enhanced Mutual-Capacitive Touch-Sensor ROIC Using an Averaging With Three Specific TX Frequencies, a Noise Memory, and a Compact Delay Compensation Circuit

To enhance the signal-to-noise ratio of a mutual-capacitive touch-sensor, three methods are used to implement read-out integrated circuit (ROIC); an averaging method with three specific transmitter frequencies of ( $n+0.5$ ) times the frequency of a gate driving signal (GCLK) of LCD with an integer $n$ , a noise memory method that eliminates the dc and low frequency noise by subtracting the noise data from the measured data, and a compact delay compensation method. A digital dual-loop phase-locked-loop generates the three specific frequencies automatically from GCLK. The proposed ROIC applied to a $14\times 16$ touch-sensor panel on a 7.9-in LCD achieves the SNR of 52.9 dB with the frame rate of 367 Hz. The ROIC chip with a 0.35- $\mu \text{m}$ CMOS process takes an area of 5.64 mm $^{{\mathrm {2}}}$ and consumes power of 29.7 mW.

An electronically tuned wideband probehead for NQR spectroscopy in the VHF range

Nuclear quadrupole resonance spectroscopy is an analytical method which allows to characterize materials which contain quadrupolar nuclei, i.e. nuclei with spin ⩾1. The measurement technology is similar to that of NMR except that no static magnetic field is necessary. In contrast to NMR, however, it is frequently necessary to scan spectra with a very large bandwidth with a span of several tens of % of the central frequency so as to localize unknown peaks. Standard NMR probeheads which are typically constructed as resonators must be tuned and matched to comparatively narrow bands and must thus be re-tuned and re-matched very frequently when scanning over a whole NQR spectrum. At low frequencies up to few MHz dedicated circuits without the need for tuning and matching have been developed, but many quadrupole nuclei have transitions in the VHF range between several tens of MHz up to several hundreds of MHz. Currently available commercial NQR probeheads employ stepper motors for setting mechanically tuneable capacitors in standard NMR resonators. These yield high quality factors (Q) and thus high SNR but are relatively large and clumsy and do not allow for fast frequency sweeps. This article presents a new concept for a NQR probehead which combines a previously published no-tune no-match wideband concept for the transmit (TX) pulse with an electronically tuneable receive (RX) part employing varactor diodes. The prototype coil provides a TX frequency range of 57MHz with a center frequency of 97.5MHz with a return loss of ⩽−15dB. During RX the resonator is tuned and matched automatically to the right frequency via control voltages which are read out from a previously generated lookup table, thus providing high SNR. The control voltages which bias the varactors settle very fast and allow for hopping to the next frequency point in the spectrum within less than 100μs. Experiments with a test sample of ZnBr2 proved the feasibility of the method.

Trends of mean temperatures and warm extremes in northern tropical Africa (1961–2014) from observed and PPCA‐reconstructed time series

AbstractTrends in daily maximum (TX) and minimum (TN) temperatures and indices of warm extremes are studied in tropical North Africa, west of the eastern African highlands, from 1961 to 2014. The analysis is based on the concatenation and cross‐checking of two observed databases. Due to the large number of missing entries (~25%), a statistical infilling using probabilistic principal component analysis was applied. Averaged over 90 stations, the linear trends of annual mean TX and TN equal respectively +0.021 °C/yr and +0.028 °C/yr. The frequency of very hot days (TX &gt; 35°C) and tropical nights (TN &gt; 20°C), as well as the frequency of daily TX and TN above the 90th percentile (p90) (“warm days” and “warm nights”), roughly follows the variations of mean TX and TN, respectively. Heat spells of TX or TN &gt; p90 are often short (usually &lt;2–3 days), and the interannual variation of their mean duration is noisier than for the other indices. Nevertheless, heat spells tend to last longer, with almost constantly positive anomalies since the mid‐1990s. The trends in March–June, the warmest season across the Sahelian and Sudanian belts, show similar variations as annual means. Overall, the local‐scale warming in annual temperatures, and in March–June, may be viewed merely as a simple shift of the probability distribution function of daily TX and TN. The correlations between the thermal indices and the 2 m temperatures suggest that the low‐frequency (&gt;8 years) variations may be viewed as a regional‐scale fingerprint of the global warming, with largest correlations in the tropical Atlantic and Indian basins, while the high‐frequency (&lt;8 years) variations should be mostly viewed as a delayed remote impact of El Niño–Southern Oscillation (ENSO) events over the region, with warm (cold) anomalies tending to follow warm (cold) ENSO events.

Experimental Studies and Verification of the Vertical Array-Differential Target Antenna Coupling (DTAC) Method for Rapid Sensing and Imaging of Subsurface Targets

We have developed a new electromagnetic geophysical system that has significantly improved target sensing and imaging capabilities compared to conventional measurements. In a previous series of papers, we described a new measurement technology called the Differential Target Antenna Coupling (DTAC) method, which used a magnetic-field transmitter (TX) and a magnetic-field receiver (RX), oriented in a horizontal array, with separation distances of the order of tens of meters, and up to tens of kilometers. In the present paper, we use the DTAC method in a vertical-array configuration, with the TX coil directly above two null-coupled RX coils. This vertical array provides a number of important advantages over the large-offset horizontal array for some applications. For example, the vertical array-DTAC method can be adapted to rapidly moving measurements, such as from a helicopter. In addition, the vertical array-DTAC method also suppresses surface clutter, such as fences, steel buildings, and parked vehicles. The DTAC method uses at least two frequencies. One frequency is used as a reference signal to establish the null direction at that frequency, and then a different frequency is used to measure the change in the null at the new frequency. We can also use an arbitrary number of frequencies with just one reference frequency for wide-bandwidth spectral measurements. We first describe the vertical array-DTAC measurement system and discuss the calibration procedure for the instrumentation. Next, we discuss the methods employed for scale-model testing of the system. We validate the vertical array-DTAC method using small-scale controlled tests and demonstrate the enhanced resolution and sensitivity of the vertical array-DTAC method. Suitable TX moments and frequency ranges can be selected for effective study of near-surface targets (civil engineering, water resource, and environmental characterization) as well as deep targets (mining and other natural-resource exploration).

Symbol Synchronization for OFDM Receivers with FFT Transport Delay Compensation

This paper proposes a new blind approach for time synchronization of orthogonal frequency division multiplexing (OFDM) receivers (RX). It is largely known that the OFDM technique has been successfully applied to a wide variety of digital communications systems over the past several years — IEEE 802.16 WiMax, 3GPP-LTE, IEEE 802.22, DVB T/H, ISDB-T, to name a few. We focus on the synchronization for the ISDB-T digital television system, currently adopted by several South American countries. The proposed approach uses the coarse synchronization to estimate the initial time reference and then, the fine synchronization keeps tracking the transmitter (TX) time reference. The innovation on the proposed approach regards to the closed loop control stabilization of the fine synchronization. It uses a smith predictor and a differential estimator, which estimates the difference between TX and RX clock frequencies. The proposed method allows the RX to track the TX time reference with high precision ([Formula: see text] sample fraction). Thus, the carriers phase rotation issue due to incorrect time reference is minimized, and it does not affect the proper RX IQ symbols demodulation process. The RX internal time reference is adjusted based on pilot symbols, called scattered pilots (SPs) in the context of the ISDB-T standard, which are inserted in the frequency domain at the inverse fast Fourier transform (IFFT) input in the TX. The averaged progressive phase rotation of the received SPs at the fast Fourier transform (FFT) output is used to compute the time misalignment. This misalignment is used to adjust the RX fine time synchronism. Furthermore, the proposed method has been implemented in an ISDB-T RX. The FPGA-based receiver has been evaluated over several multipath, Doppler and AWGN channel models.

A Novel Hybrid Phased Array Antenna for Satellite Communication on-the-Move in Ku-band

This paper introduces a novel waveguide hybrid phased array (HPA) for mobile satellite communications operating in Ku-band. The array is low profile and low cost, adopting an electrical scan in elevation and mechanical scan in azimuth to track satellites. High directivity and wide bandwidth impedance is provided by a dual linear polarized waveguide radiating element that covers both Rx and Tx frequencies within the band. The vertical and horizontal polarizations are excited by direct feeding and slot coupled aperture feeding, respectively. The array structure of $32 \times 12$ elements is split into inclined and interlaced 12 subarrays 225 mm in height. The feed networks and duplexers are designed in unconventional waveguide sizes. In the system, there are 12 independent receiving (Rx) and transmitting (Tx) modules with phased shifter components, which realize beam and polarization tracking. The system is designed to track satellites by scanning $15^\circ{-}75^\circ$ (relative to the ground plane) electrically in the elevation and $0^\circ{-}360^\circ$ mechanically in the azimuth. The array has been successfully developed and measured. The maximal gain loss in scanning range is about 4.0 dB.

Two High KDPI Kidneys Are Better Than One: Opportunities to Expand Dual Kidney Transplantation to Reduce Discard Rates.

Background: OPTN policy permits both kidneys to be allocated to the same patient if at least two of the following donor criteria are met: age>60, eCrCl<65 ml/min based on admission creatinine (Cr), rising Cr (>2.5mg/dl), longstanding hypertension or diabetes, 15%<glomerulosclerosis<50%. The OPTN Kidney Transplantation Committee (KTC) is evaluating data to assess whether changes to this policy would help increase organ utilization. Methods: Cox models for graft survival adjusting for log(KDRI), recip age, diabetes status, and procedure type (single vs. dual) were estimated using solitary, primary, adult, deceased donor kidney recipients from 2000-2007 per the OPTN database. Organ allocation and disposition data from 2012 were also assessed. (En bloc tx were analyzed separately but not included here.) Results: In 2012, OPOs reported that only 207 (3%) kidney donors were eligible for dual allocation under current policy, and only 87 dual tx occurred. The frequency of dual tx has decreased in recent years (170 were performed in 2005). Yet dual tx confers substantially lower risk of graft failure (HR=0.82, p<0.001), with an improved survival most pronounced for high KDPI kidneys.Figure: No Caption available.Of the 2,759 kidneys discarded in 2012, 2,126 (77%) were recovered from the same donor. Of these, 1,004 were from the same KDPI>85% donor. While relatively few of the 1,004 were reported discarded due to anatomical abnormalities (6%), diseased organ (4%), vascular damage (1%), organ trauma (1%), or infection (0%), more than two thirds were discarded due to “biopsy findings” (42%) or “list exhausted” (26%). Conclusions: These results show that dual tx appears to lessen the detrimental effect of high KDPI and that more opportunities for dual tx may exist than are currently being realized. The KTC is evaluating whether revisions to policy (e.g., basing dual eligibility on KDPI) and the match system (e.g., allowing offer screening based on single vs. dual) are needed to encourage the dual use of kidneys that confer a survival benefit over dialysis but would otherwise be discarded.

SETTING AN OPTIMAL IMAGE PARAMETER IN AN ULTRASOUND SYSTEM

Embodiments of setting an optimal image parameter for obtaining an optimal ultrasound image are disclosed. In one embodiment, by way of non-limiting example, a processing unit is configured perform an image process upon an ultrasound image to thereby detect a center of a blood vessel from the ultrasound image. The processing unit is configured to set the center of the blood vessel as an optimal focal point position. The processing unit is configured to calculate a plurality of steering angles, a plurality of transmit (Tx) frequencies and a plurality of sound speeds. The processing unit is further configured to form a plurality of ultrasound images corresponding to each of the steering angles, the Tx frequencies and the sound speeds based on the ultrasound data, detect a signal to noise ratio (SNR), a number of edge points of the blood vessel and a contrast difference between pixels for each of the second ultrasound images to thereby detect an optimal steering angle, an optimal Tx frequency and an optimal sound speed.

Dual-Band Horn Array Design Using a Helical Exciter for Mobile Satellite Communication Terminals

A horn array antenna is proposed for dual-band and dual-polarization operation. The array is optimally designed to be used as a feeder in mobile satellite terminals with a hybrid antenna (HA) structure, but it can be also used independently as a phased array. The array has an oval-shaped rim to maximize the efficiency of the HA, and is composed of 20 horn elements in a hexagonal structure. The element has a horn radiator with a conical helix, which is placed inside the horn and excited by two ports for TX and RX at both ends. Therefore, the antenna can be simultaneously operational in the Ka-band TX and K-band RX frequency bands, using a compact structure providing left-hand circular polarization (LHCP) for TX and right-hand circular polarization (RHCP) for RX. The fabricated array is connected with active channel modules having 20 channels each for TX and RX, and it was experimented on within a beam scanning range of -5° to +5° in the azimuth and elevation directions using phase control of the ac tive channel module. The antenna has a minimum gain of 21.7 dBi over the TX band and 19.7 dBi over the RX band over the desired scan region. The maximum pointing error is about 0.32° and the pointing loss is approximately 1.3 dB. In addition to meeting the above RF requirements, the antenna is designed to meet environmental specifications such as wind loads as required for mobile terminals.

Unbalanced-to-Balanced and Balanced-to-Unbalanced Diplexer With High Selectivity and Common-Mode Suppression

Two novel balun diplexers based on stub-loaded resonators are presented and carefully examined in this paper. Besides being diplexers, the two balun diplexers are also interface devices between a single-ended (differential) antenna and differential (single-ended) receiver and transmitter. The stub-loaded resonator not only has an extra degree of freedom to realize the anticipant coupling scheme, but it also can compact the circuit size and enlarge the frequency separation of the first differential- and common-mode resonant frequencies. The design procedure of the balun filter with three 50- Ω ports is introduced based on a symmetric four-port balanced-to-balanced bandpass filter. Two demonstrated balun diplexers, unbalanced-to-balanced and balanced-to-unbalanced diplexers, with Rx and Tx frequencies at 1.84 and 2.45 GHz are designed, fabricated, and measured. The implemented balun diplexers present an excellent in-band balanced performance with common-mode rejection ratio better than 38 dB over the passbands. High selectivity and isolation are also obtained by giving a cross-coupling scheme for both Rx and Tx balun filters.

Effect of adherence to monthly zoledronic acid treatment on risk and frequency of skeletal complications and follow-up duration in breast cancer patients

9593 Background: Bone is the most common site of metastasis in breast cancer patients (pts). Clinical trials and outcome studies have demonstrated benefit of zoledronic acid (ZA) in reducing risk of skeletal complications (SC). This study explored relationships between persistency on ZA and the intended treatment (TX) outcomes. Methods: Female breast cancer pts with first bone metastasis (BM) diagnosed between Jan 03 to Oct 06 were identified from PharMetrics database. Persistency was defined as duration from initiating ZA TX to date of first TX gap of &gt;45 days. Pts were divided into short (≤90 days, 230 pts), medium (91–180, 171 pts) and long (&gt;180, 313 pts) persistency groups. TX selection bias was handled by calculating propensity scores using year of first BM diagnosis, having other metastases or &gt;1 BM claim, use of opioids and oral bisphoshonate before BM. Propensity scores, age and Charlson's Comorbidity Index (CCI) were included in multiple regressions to investigate impact of ZA persistency on follow-up duration, risk and rate of SC. Results: 2394 pts were enrolled, with 714 (29.72%) ZA treated. Three persistency groups had similar age. Short group had higher CCI than long group (mean 8.53 vs 8.34, p&lt;0.05). Frequency of ZA TX decreased over time in all groups. For short, medium and long persistency groups, means of follow-up durations were 9.8 (median, 7.0), 13.0 (9.0), 19.3 (18.1) months, and means of time to first SC after BM were 249 (median: 167), 323 (217), 418 (365) days. Means of SC rates were 0.27, 0.21, and 0.12 per month for patients who experienced at least 1 SC among the three groups. Medium and long persistency groups had 41% and 139% longer follow-up than short group (p&lt;0.05). Long group had lower risk of SC than short group (HR=0.576, p&lt;0.05). In patients who developed at least 1 SC, long group experienced 39% less SCs (p&lt;0.005) than short group. Conclusions: TX with zoledronic acid in breast cancer pts with BM positively impacts the risk, frequency of SC and follow-up duration. Also, longer persistency on ZA TX is associated with significantly longer follow-up and lower risk of SC. [Table: see text]

Flat Array Antennas for Ku-Band Mobile Satellite Terminals

This work presents the advances in the development of two innovative flat array antennas for Ku-band mobile satellite terminals. The first antenna is specifically conceived for double-deck trains to allow a bi-directional high data rate satellite link. The available circular surface (diameter 80 cm) integrates both a transmitting and a receiving section, operating in orthogonal linear polarizations. The TX frequency range is fully covered while the RX bandwidth is around 1 GHz arbitrarily allocated on the DVB range depending on requirements. The beam is steered in elevation through a phased array architecture not employing costly phase shifters, while the steering in azimuth is mechanical. Active BFNs allow excellent performance in terms of EIRP and G/T, maintaining extremely low profile. High antenna efficiency and low fabrication cost are ensured by the employment of innovative SIW (Substrate Integrated Waveguide) structures. The second antenna, receiving-only, is designed for radio/video streaming services in mobile environment. Full DVB coverage is achieved thanks to cavity-backed patches operating in double linear polarization. Two independent broadband active BFNs allow simultaneous reception of both polarizations with full tracking capabilities and a squintless beam steering from to in elevation. A minimum gain of 20 dBi and G/T &gt; dB/ are achieved, while maintaining extremely compact size and flat profile. In the design of both antennas fabrication cost is considered as a driving factor, yet providing high performance with a flat profile and thus resulting in a great commercial potentiality.