RF Blocks Research Articles

Structural carbon fiber plastics as a promising material for radio-absorbing materials creation

Radio-absorbing materials (RAM) are widely used in the radio industry and instrumentation when creating anechoic chambers, loads, absorbers in waveguide and other microwave devices, to reduce the radar visibility of products and objects of military equipment, to combat “parasitic” connections between blocks and components of RF blocks, to protect personnel from microwave radiation. RAMs based on polymer binder and special fillers have found the most widespread application for solving these problems, but such materials are not capable of carrying structural loads. One of the likely solutions to this problem may be the use of carbon fiber plastics produced in large quantities by the domestic industry.

A Ka-Band SATCOM Transceiver in 65-nm CMOS With High-Linearity TX and Dual-Channel Wide-Dynamic-Range RX for Terrestrial Terminal

In this article, a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Ka$ </tex-math></inline-formula> -band satellite communication (SATCOM) transceiver is first presented using a standard CMOS technology. The proposed <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$Ka$ </tex-math></inline-formula> -band SATCOM transceiver consists of a high-linearity transmitter (TX) and dual-channel receiver (RX); both TX and RX are based on direct-conversion architecture. By implementing the dual-channel RX, multiple multiplexing modes, including polarization multiplexing and frequency multiplexing, can be enabled depending on the application. The RX variable gain is distributed in both RF blocks and baseband blocks to achieve a wide input dynamic range. The LNA employs a dual-coupling transformer for a low-noise figure (NF) and wideband input matching; moreover, it enhances the amplifier unilateralization characteristic to mitigate the loading effect from switched attenuators. An adjacent channel interference (ACI) cancellation scheme is proposed to further enhance the RX linearity in the frequency multiplexing mode. In the TX, single-turn high-quality-factor transformer is employed to realize matching network and four-way power combining. A prototype of the SATCOM transceiver is fabricated in a standard 65-nm CMOS process. Under 1.05-V supply voltage, the TX achieves a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$P_{\mathrm {SAT}}$ </tex-math></inline-formula> of 20.5 dBm and an average output power of 12 dBm with 2% error vector magnitude (EVM) and a 37.6-dB ACPR. The dual-channel RX achieves an NF of 5.4 dB, an IIP3 of −30 dBm on the high-gain mode, the ACI cancellation is measured of 7.9 dB with a 100-MHz signal bandwidth.

On the beamforming design of millimeter wave UAV networks: Power vs. capacity trade-offs

The millimeter wave (mmWave) technology enables unmanned aerial vehicles (UAVs) to offer broadband high-speed wireless connectivity in 5G/6G networks. However, the limited footprint of a single UAV implementing analog beamforming (ABF) requires multiple aerial stations to operate in swarms to provide ubiquitous network coverage, thereby posing serious constraints in terms of battery power consumption. A possible remedy is to investigate the concept of hybrid beamforming (HBF) transceivers, which use a combination of analog beamformers to achieve higher flexibility in the beamforming design. This approach permits multiple ground users to be served simultaneously by the same UAV, despite involving higher energy consumption than its ABF counterpart. This paper presents a tractable stochastic analysis to characterize the ergodic capacity and power consumption of UAV mmWave networks, focusing on the trade-off between ABF and HBF architectures. A multi-beam coverage model is derived as a function of several UAV-specific parameters, including the number of UAVs, the deployment altitude, the antenna configuration, and the beamforming design. Our results show that, while ABF achieves better ergodic capacity at high altitudes, an HBF configuration with multiple beams, despite the use of more individually power-hungry RF blocks, always consumes less total power with limited capacity degradation.

Efficient technique for real-time face detection

Currently, the top-performing face detectors use Convolution Neural Networks (CNN). These detectors have high performance but require large computational resources. Hence, it is a challenge to use these for practical applications with limited resources. To address this problem, this research paper proposes a single-stage face detector for practical applications with better accuracy and speed. The proposed face detector is a lightweight and fast CNN-based face detector. To achieve fast detection speed, by swiftly reducing the size of the input feature space through a carefully designed architecture using depth-wise convolution and Receptive Field Blocks (RBF). The high accuracy of the method is achieved by preserving the feature information from the early layers using CReLU (Concatenate Rectified Linear Units) activation in the CNN architecture. To detect faces of different pixel sizes, we used parallel RF blocks, which use multiple filters of different kernel sizes and dilation. The proposed method was tested on benchmark datasets such as WIDER FACE, AFW, and PASCAL faces, and performed well when compared to recent state-of-the-art real-time face detection algorithms.

RF Blocks for Biomedical Engineering

Biyomedikal mühendisliği uygulamaları için Radyo Frekansı (RF) güç amplifikatörü (PA), güç osilatörü (PO), mikser ve test devresi simülasyon sonuçları sunulmuştur. Yeni bir Sınıf-E tipi RF PA tasarlandı ve şematik devre simüle edildi. RF devre blokları 130 nanometre (nm) standart CMOS RF teknolojisinde tasarlanmış ve uygulanmıştır. Şematik test devresi simülasyonları, spiral endüktansı ve anten iç direnci içeren anten bağlantısı ile test edilmiştir. Devre simülasyon sonuçlarına göre, PA, PO ve mikser çıkışı ile anten giriş katları arasında ekstra uyumsuzluk ayar devresine ihtiyaç duyulmadı. Gösterim amacıyla, 33 GHz çok yüksek frekans (EHF) bandı PA giriş voltajı, 300 mV tepeden tepeye (pp) voltaj seviyesinde uygulanmıştır. Sınıf-E tipi aktif transistör anahtarı olarak teknoloji standardı 1V RF n-kanallı Metal-Oksit-Silikon (MOS) transistör kullanıldı. PA devre simülasyonu için test sonuçları, önerilen devrenin geleneksel E Sınıfı tipi RF PA' lardan daha iyi çalıştığını göstermektedir. 40 harmonik için 33 GHz RF giriş frekansında -8,5 dBm güç girişi için % 70 güç amplifikatörü verimliliği (PAE) ve harmonik salınım dengesi modunda 15 adımuygulanmıştır. Tümdevre blokları, özellikle glükoz algılama sistemi için talep edilen biyomedikal mühendisliği için tasarlanmış ve yapılmıştır. Yeni bir Radyo Frekansı (RF) güç osilatörü (PO) devresi tasarlandı ve simülasyon sonuçları da sunuldu. PO devre konsepti, giriş ve çıkış arasında anahtar elemanı olarak tek nMOS transistör kullandığından son derece kullanışlıdır. Aynı zamanda RF devrelerinin verici tarafı için osilatör devresinin kullanımını ortadan kaldırmaktadır. Osilatör devreleri genellikle n-kanal ve p-kanal standart CMOS teknoloji transistörleri ile negatif dirençli harmonik çapraz bağlı LC-tank voltaj kontrollü osilatör (LCVCO) devre yapısı kullanılarak uygulanmıştır. Verici (Tx) tarafında geleneksel olarak kullanılan LCVCO devresinin ortadan kaldırılması, özellikle iç mekan kablosuz telekomünikasyon ve biyomedikal mühendislik sistemleri için önemlidir, çünkü bu yöntem kullanılarak önemli miktarda güç kaybı ortadan kaldırılır. PO' nun uygulanması için, PA devresi gerçekleştirme adımında gösterilen E Sınıfı tipi RF PA modifiye edildi. Sorumlulukları hem salınım sinyali üretmek hem de gücünü anten yüküne yükseltmektir. Bu amaçla, RF PO da aynı 130 nm standart CMOS RF teknolojisinde tasarlandı ve uygulandı. Ana besleme voltajı vdd ve öngerilim voltajı vbias1 600 mV değerlerine ayarlandı. Güç kaynaklarından 35.6 GHz RF güç salınım frekansında toplam 8.94 miliwatt (mW) ortalama kare kök (rms) güç ve 14.9 miliamper (mA) rms akım sağlandı. Bu, tek transistör ile milimetre dalga (mmWave) çok yüksek frekans (EHF) bant (30-300 GHz) RF güç salınımı oluşturan ilk çalışmadır. Glükoz algılama yapısının tüm devre gerçekleştirilmesinin son adımında, EHF bandında mm-Dalga frekansında çalışan yeni RF mikser devresi gösterilmektedir. Bu mikser devresi tamamen yeni bir tasarımdır ve dünyada ilk kez burada sunulmuştur. Yeni konsept tek transistör karıştırıcı devresinin gerilimini ve akımını beslemek için besleme gerilimi kullanmak yerine, önceki adımda tanıtılmış olan PO benimsenmiştir. PO, hem besleme voltajını hem de akımı sağlıyor, ayrıca temel bant salınım sinyalini de getiriyor. Bu yöntemle hem güç kaynağı hem de temel bant osilatör sinyali oluşturuldu. Bu yöntem ayrıca yaygın olarak kullanılan harmonik çapraz bağlı negatif direnç geri besleme CMOS LCVCO devresini de ortadan kaldırmaktadır. Öte yandan, karmaşık Gilbert Mixer mimarisini kullanmak yerine, yeni tek transistör devre tasarım konsepti kullanıldı. Tek transistörlü karıştırıcı devresi, yalnızca bir n-kanal MOS transistörüne sahip olan düşük gürültülü amplifikatörün (LNA) kullanımına benzer. Önerilen karıştırıcı devre tasarım şemasına göre, zarf sinyalinin ikinci harmonik çıkarımı elde edilmiştir. 130 nm standart CMOS teknolojisi kullanılmıştır. 35.6 GHz frekanslı PO sinyali ve 34 GHz RF test sinyali karıştırıldı ve 3.12 GHz 2. harmonik zarf çıkarıldı. Bu çalışmanın sadece bir değil, birçok yeni tasarım konsepti vardır.

Fixed Frequency Beam-Scanning HMSIW-Based Leaky-Wave Antenna Composed of Circular Slots in V-Shape Configuration

A new reconfigurable slotted antenna is presented in this manuscript. The proposed antenna is realized on a half-mode substrate integrated waveguide (HMSIW). The beam-steering is achieved using embedded varactor diodes in circular cells. Sweeping the bias voltage causes variations of the phase constant, which leads to the fixed frequency beam-scanning. Each reconfigurable cell includes a circular slot at the top plate and varactor switch, DC block, and RF block at the backside of the structure. The operating frequency is chosen as 28.5 GHz in the support of the upcoming 5G mm-wave communications systems. The proposed antenna beam scans 29° of space by switching among different states at 28.5 GHz. The length, width, and height of the antenna are 67 mm, 48 mm, and 0.32 mm, respectively. The proposed antenna’s main novelties are compactness and electronic beam-scanning capability using a single switch per cell. The measured peak realized gain and sidelobe level (SLL) at 28.5 GHz are 8.2 ± 0.6 dBi and 5 dB, respectively. While the impedance bandwidth of the proposed antenna is 1.5 GHz. A good agreement between measured and simulated results is observed. The discrepancies are investigated through a sensitivity analysis. Fixed frequency beam-scanning capability, compactness, simplicity of the assembly, backward radiation, and slight gain variation of the proposed antenna make it a suitable candidate for blind-spot monitoring and 5G vehicle to everything (V2X) communications.

Receiver Designs for Electronic Toll Collection Systems : A Survey

&lt;p&gt;This paper discusses about different receiver designs adopted so far for various electronic toll collection systems. A comparative analysis based on the discussions is also provided. It shows that each design has it's own advantages and disadvantages compared to others. The main aim of this paper is to identify the most suitable design. The researches shows that the receiver design described in the 5.8GHz digitally controlled DSRC receiver for Chinese electronic toll collection system is the most suitable one. Here all RF, IF blocks and digital baseband for on-chip automatic gain control, are integrated on an RF-SoC. The proposed digitally controlled LNA and mixer circuits are elaborated. The technology used is 0.13μm CMOS technology. The RF block occupies a chip area of 0.75mm2. It consumes 22mA under a 1.5V supply voltage. The bit error rate maintains better than 10-6, the input power level varies from -75dBm to -8dBm. This design provides a receiver sensitivity improvement of at least 25%, and a dynamic range enhancement of at least 12%.&lt;/p&gt;

A 580- $\mu$ W 2.4-GHz ZigBee Receiver Front End With Transformer Coupling Technique

This letter presents a 2.4-GHz sliding-IF ZigBee receiver front end for wireless sensor networks. The receiver targets extreme high energy efficiency by sharing its power between all RF blocks. It employs a 0-V supply passive gain booster and mixers combo with its power coupled from the voltage-controlled oscillator (VCO) by using the transformer coupling technique. The quasi-passive mixer and quadrature passive mixer down converts the RF signal to the baseband without need of the dc supply voltage. The VCO achieves a phase noise of −110 dBc/Hz at 1 MHz while dissipating $580~\mu \text{W}$ . The RF front end demonstrates the conversion gain of 13.5 dB, noise figure of 6.1 dB, and IIP3 of −9.4 dBm at the frequency band of 2.41–2.53 GHz.

Alternative technological development for RF hybridization

The paper presents a technological solution for high frequency packaging platform evaluated up to 40 GHz. The main purpose of this development was to define an alternative hybrid technology that is more flexible and faster to prototype compared with thin film or multi chip module (MCM-D). The alternative technology also shows adequate performance for high bit rate solutions integrating optical and electronics blocks. This approach consists of a soft substrate (laminate material), plating processes (electroless Ni–P/Au, electrolytic Au) and lithography patterning. Ground coplanar waveguide was used for microwave structures with excellent ground planes connections due to easy via holes implementation. We present results of high frequency packaging of important RF blocks, such as integrated broadband bias-T, transimpedance amplifier ICs and silicon photonics optical modulators. The paper demonstrates a solution for high frequency hybridization that can be implemented with standard substrates, designed with any shape and with large numbers of metalized via holes and compatible with usual assembling techniques.

Fundamental cavity impedance and longitudinal coupled-bunch instabilities at the High Luminosity Large Hadron Collider

The interaction between beam dynamics and the radio frequency (rf) station in circular colliders is complex and can lead to longitudinal coupled-bunch instabilities at high beam currents. The excitation of the cavity higher order modes is traditionally damped using passive devices. But the wakefield developed at the cavity fundamental frequency falls in the frequency range of the rf power system and can, in theory, be compensated by modulating the generator drive. Such a regulation is the responsibility of the low-level rf (llrf) system that measures the cavity field (or beam current) and generates the rf power drive. The Large Hadron Collider (LHC) rf was designed for the nominal LHC parameter of 0.55 A DC beam current. At 7 TeV the synchrotron radiation damping time is 13 hours. Damping of the instability growth rates due to the cavity fundamental (400.789 MHz) can only come from the synchrotron tune spread (Landau damping) and will be very small (time constant in the order of 0.1 s). In this work, the ability of the present llrf compensation to prevent coupled-bunch instabilities with the planned high luminosity LHC (HiLumi LHC) doubling of the beam current to 1.1 A DC is investigated. The paper conclusions are based on the measured performances of the present llrf system. Models of the rf and llrf systems were developed at the LHC start-up. Following comparisons with measurements, the system was parametrized using these models. The parametric model then provides a more realistic estimation of the instability growth rates than an ideal model of the rf blocks. With this modeling approach, the key rf settings can be varied around their set value allowing for a sensitivity analysis (growth rate sensitivity to rf and llrf parameters). Finally, preliminary measurements from the LHC at 0.44 A DC are presented to support the conclusions of this work.

The Evolution of Channelization Receiver Architecture: Principles and Design Challenges

This paper presents a broadband receiver architecture with series and parallel channelization. The proposed architecture decomposes the broadband incident spectrum into multiple channels, and achieves fast switching time, while using the single synthesizer with a fixed local oscillator (LO) frequency. Channelized receiver is a good candidate for critical RF processing tasks, such as data conversion, broadband radio, and spectrum analysis. The key feature of the proposed channelized receiver is the decomposition of the broadband frequency spectrum through parallel band partition and series channel selection. Relevant design challenges of the channelization receiver are discussed. In addition, the radio impairments determining the key performance of the radio are analyzed. The prototype receiver front-end was designed and implemented in 45 nm CMOS technology to demonstrate the effectiveness of the proposed architecture. The receiver front-end prototype splits an input spectrum of dc-40 GHz into four sub-bands with 10 GHz IF bandwidth and dissipates the average power of 33 mA and 60 mA from RF and LO blocks, respectively, while achieving <5 dB NF and <−145 dBc/Hz phase noise.

A 190 nA Bias Current 10 mV Input Multistage Boost Regulator With Intermediate-Node Control to Supply RF Blocks in Self-Powered Wireless Sensors

Self-powered wireless sensors require power delivery systems capable of harvesting from very low input voltage while consuming minimal bias current. This paper presents a multistage boost regulator capable of generating 3 V to supply RF blocks in self-powered wireless sensors from 10 mV input voltage. The bias power consumption is minimized using automated bias gating. The efficiency of the multistage conversion at a high conversion ratio is enhanced through the regulation and control of the intermediate-node voltage. A test chip, fabricated in 130 nm CMOS, demonstrates functional operation from as low as 10 mV input and consumes 190 nA bias current. Single-stage boost regulator demonstrates Peak efficiency of 89%, while the cascaded two stage peaks at 72%. In the cascaded system, the variable intermediate-node voltage operation shows up to 9% efficiency improvement over fixed intermediate-node voltage when operating at high conversion ratio.

Comparison of clonidine and fentanyl as adjuvant to ropivacaine in spinal anesthesia in lower abdominal surgeries.

Background:Ropivacaine, a newer local anesthetic, is gaining increased acceptance due to its improved safety profile over bupivacaine and lignocaine. Analgesic adjuvants have proved to be valuable in improving the quality of anesthesia and duration of analgesia.Aim:To compare the efficacy of clonidine and fentanyl as adjuvants to ropivacaine in spinal anesthesia in lower abdominal surgeries.Materials and Methods:A randomized, double-blind control study was carried out in 100 patients who were randomly divided into two groups. Ropivacaine-clonidine group (RC) received 30 μg of clonidine with 18.75 mg of 0.75% isobaric ropivacaine, Ropivacaine-fentanyl group (RF) received 25 μg of fentanyl with 18.75 mg of 0.75% isobaric ropivacaine intrathecally. The onset and duration of sensory and motor block, hemodynamic parameters, quality of surgical analgesia, total analgesia time, sedation score, and side effects were statistically analyzed using SPSS statistical package, paired and unpaired t-tests and Chi-square test.Results:The duration of sensory block in RC (240.00 ± 20.99), RF (196.80 ± 18.34), and motor block in RC (192.20 ± 17.36), RF (139.20 ± 17.93) outlasted the duration of surgery. In clonidine group, there was significant prolongation of sensory block, motor block and the total analgesia time. Hypotension and bradycardia occurred more commonly in RC group, whereas pruritus was more in RF group.Conclusion:Ropivacaine when combined with either clonidine or fentanyl provided an adequate subarachnoid block for lower abdominal surgeries. As an adjuvant, clonidine has advantage over fentanyl as it increased the duration of the subarachnoid block and the postoperative analgesia.

A Sub-GHz Mostly Digital Impulse Radio UWB Transceiver for Wireless Body Sensor Networks

This paper presents a mostly digital impulse radio (IR) ultra-wideband (UWB) transceiver for low power wearable and implantable biomedical devices. The UWB transmitter adopts carrier-less all-digital pulse generator with on-off keying (OOK) modulation, and uses an 11-bit Barker code for reliable communication in the frequency range of 0-960 MHz. The receiver is based on auto-threshold detection. The only RF block in the receiver is the low-noise amplifier (LNA), and this LNA operates intermittently for better power efficiency. The timing window for incoming data is provided by a delay locked loop (DLL). This DLL could synchronize the receiver clock to the incoming data. Fabricated in a standard 0.35- μm CMOS technology, the prototype chip achieves energy efficiency of 100 and 600 pJ/pulse for the transmitter and receiver, respectively.

A Programmable Calibration/BIST Engine for RF and Analog Blocks in SoCs Integrated in a 32 nm CMOS WiFi Transceiver

This paper presents a flexible and portable digital framework for Built-in Self-Test (BIST) and calibration of RF/analog circuitry. Novel to the proposed testing framework, is a reusable, flexible, drop-in IP core, composed of a centralized custom processing engine with data path, memory architecture and instruction set optimized for efficient execution of compute intensive test and calibration algorithms. The innovative BIST engine is complemented with a calibration and test sequencing methodology exploiting the embedded test hardware, to dynamically correct for transceiver imbalances and non-idealities, as well as to estimate performance parameters such as Error Vector Magnitude (EVM). The engine has been integrated with a WiFi transceiver in a 32 nm SoC test chip to demonstrate the functionality of this framework. This implementation covers an area of 0.63 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and provides similar performance (e.g., improvements up to 10 dB in EVM for Rx IQ imbalance compensation) to off-chip testing without relying on expensive equipment.

Adhesive Plaster-Type Human Activity Monitoring Device

In this study, the development of an adhesive plaster-type human activity monitoring device is presented. It is a wearable sensor system designed for monitoring human activity and health conditions to improve safety, healthcare and the quality of life. The device is attached on the human's chest for monitoring vital signals — electrocardiogram (ECG) and physical environmental information — acceleration, humidity, pressure and temperature. The entire device can fabricated within a 110 x 22 mm 2 area and is only 7 grams. Because of the small size and low weight, it can be worn comfortably. I. INTRODUCTION In recent years, the proportion of patients with lifestyle-related diseases caused by poor dietary habits, overwork and stress are increasing significantly. Moreover, due to the birthrate decline, improvements in health care and medicine, the elderly population is also increasing rapidly. To improve health, the quality of life and the prolonged medical care for elderly people, daily activity monitoring is becoming more important. To achieve this, we have realized a small-sized and low-weight adhesive plaster-type human activity monitoring device which can be comfortably and conveniently worn on the chest for monitoring the user's ECG, acceleration, humidity, pressure and temperature. II. DEVICE DETAILS Figure 1 and 2 show the block diagram and image of the monitoring device, respectively. The entire device is composed of three blocks - the Main block, RF block and Power block, and stretchable wiring is used to connect each block to allow flexibility. The device can be fabricated with an area of 110 x 22 mm 2 and is only 7 grams. The main block is composed of an ECG amplifier circuit, a 3-axes accelerometer, an altimeter sensor, humidity sensor, temperature sensor and an 8051 MCU. The RF block is equipped with a Bluetooth module. The power block is composed of a regulator and a typical coin-sized rechargeable lithium-ion battery (3.7V, 75 mAh).

Comparison of clonidine versus fentanyl as an adjuvant to intrathecal ropivacaine for major lower limb surgeries: A randomized double-blind prospective study

Background: Ropivacaine is a newer local anesthetic, proven to have a better safety margin than bupivacaine and lignocaine. While maintaining this advantage and improving the intraoperative quality of anesthesia, the use of analgesic adjuvants has been proven to be valuable. Aim: To compare the efficacy of clonidine and fentanyl as adjuvants to intrathecal isobaric ropivacaine for major lower limb surgeries. Settings and Designs: Randomized double-blind control trial. Materials and Methods: Seventy patients were randomly divided in two groups. Ropivacaine-Clonidine group (RC) received 60 mcg of clonidine with 15 mg of 0.5% isobaric ropivacaine, Ropivacaine Fentanyl group (RF) received 25 mcg of fentanyl with 15 mg of 0.5% isobaric ropivacaine intrathecally. The onset and duration of sensory-motor block were recorded. The total analgesia time, sedation score, hemodynamic parameters, and side-effects were noted. Statistical Analysis: SPSS statistical package was used for statistical analysis. Paired and unpaired t-test, analysis of variance and chi-square test were used for statistical calculation. Result: The duration of sensory block in RC (329.42 ± 33.86), RF (226 ± 46.98), and motor block in RC (248.51 ± 55), RF (212.60 ± 43.52) out lasted the duration of surgery (125.61 + 64.46). In clonidine group, there was significant prolongation of sensory block (P < 0.001), motor block (P < 0.01) and the total analgesia time (P < 0.001). Hypotension and bradycardia occurred in 8.6% patients in clonidine group, whereas pruritus was experienced by 8.6% patients in fentanyl group. Conclusion: Ropivacaine when combined with clonidine or fentanyl provided adequate subarachnoid block for major surgeries, wherein clonidine has advantage over fentanyl as it increased the duration of subarachnoid block and prolonged the postoperative analgesia.

SSC Past-President Willy Sansen Chairs Post-ISSCC Short Course on RF Blocks for Wireless Transceivers: Recorded Presentations Online at isscc.org [Conference Reports

SSC Past-President Willy Sansen Chairs Post-ISSCC Short Course on RF Blocks for Wireless Transceivers: Recorded Presentations Online at isscc.org [Conference Reports

Clamping Op-Amp를 이용한 광대역 로그 비디오 증폭기의 선형성 개선에 관한 연구

본 논문은 0.5~2.0 GHz에서 -70~0 dBm의 동적 범위를 갖는 로그 비디오 증폭기(Successive Detecting Log Video Amplifier, 이하 SDLVA)를 설계 및 제작하였다. 제작된 SDLVA는 5단의 증폭기를 이용한 고주파 출력부, 2단의 로그검파기 그리고 선형성 개선을 위하여 클램핑 연산증폭기를 이용한 가산 회로로 구현하였다. 제작된 SDLVA의 측정 결과는 73 dB 이상의 소신호 이득과 10.1~12.2 dBm의 고주파 포화 출력 특성을 갖는다. 그리고 -70~0 dBm 입력 시 25 mV/ dB<TEX>${\pm}$</TEX>1.0 mV의 기울기를 갖고 <TEX>${\pm}$</TEX>1.5 dB 이하의 선형 특성을 갖는 비디오 신호를 출력한다. This paper describes a design and fabrication of SDLVA. The SDLVA operates 0.5~2.0 GHz with -70~0 dBm dynamic range. The SDLVA is consisted of 5-stage RF block, 2-stage detector block and summation circuit using clamping op-amp to improve video linearity. The result of measure, SDLVA of RF path has over 73 dB small-signal gain and 10.1~12.2 dBm saturation power. The video path has 25 mV/ dB<TEX>${\pm}$</TEX>1.0 mV and under <TEX>${\pm}$</TEX>1.5 dB video linearity.

Cryogenic Test-Bed Applied to 9 K NbN RSFQ Devices Operation

NbN RSFQ circuits operating at 9 K reduce the cooling constraints especially for portable, remote, telecoms or medical imaging applications. We have developed a test-bed to study the operating temperature of the various mixed RF and digital circuit blocks of NbN ‘HyperSCAN’ project test vehicle 1 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\rm cm}^{2}$</tex></formula> chips. The use of a widespread helium cryostat (‘Orange-ILL’) allows us to stabilize the chip temperature in the range 2.9 K–20 K with thermal oscillations lower than 0.1 K. The chip is mounted on a PCB and shielded from the external field: the PCB provides a multi-connection packaging used in order to study temperature and frequency operation of 30 GHz NbTiN CPW filters, RSFQ gates, analog SQUID and NbN/TaN/NbN SNS junctions arrays. The comparison between electrical simulations and tests is made on flexible, <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">$\sim$</tex></formula> 56 cm long, micro-strip line ribbon cable carrying 32 signals each including bias lines, in the range of DC-3 GHz, combined with 4 semi-rigid <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\sim$</tex> </formula> 40 GHz coaxial cables. By removing spurious resonances, it is expected to take full benefit of the large bandwidth, low insertion loss and low thermal conductivity of the set-up. We emphasis on the flexibility, large yield, reliability and reduced cost of such packaging coupled to He cooling exchanger for applying to testers and to future 9 K NbN multi-ADC green and remote systems when only low electrical power sources are available.