Single Band Modulation Research Articles

High-Isolation Multimode Multifunction 24-/60-GHz CMOS Dual-Bandpass Filtering T/R Switch

Fully integrated 24-/60-GHz dual-band transmit/receive (T/R) switch capable of bandpass filtering and switching operations in single bands and concurrent dual band, coupled with simultaneous transmission and reception, is developed using a 0.18- $\mu \text{m}$ SiGe BiCMOS process. The developed bandpass filtering switch can also function as a diplexer with switching functions. The measured insertion losses of the T/R switch are 2.9 and 8.7 dB at 24 and 60 GHz in single-band modes and 3/8.8 dB at 24/60 GHz in concurrent dual-band mode, respectively. The measured isolations are 53 and 43 dB at 24 and 60 GHz in single-band modes and 50/57 dB at 24/60 GHz in concurrent dual-band mode, respectively. The measured inputs $P_{1-\text {dB}}$ are 20.6 and 16.4 dBm at 24 and 60 GHz in single-band modes and 15.9/13 dBm at 24/60 GHz in concurrent dual-band mode, respectively. The measured inputs IP3 are 23.2 and 22.5 dBm at 24 and 60 GHz in corresponding single-band modes, respectively. The total chip size is $1480~\mu \text{m}\times 520~\mu \text{m}$ excluding all the RF and dc pads.

Picosecond timing of microwave Cherenkov impulses from high-energy particle showers using dielectric-loaded waveguides

We report on the first measurements of coherent microwave impulses from high-energy particle-induced electromagnetic showers generated via the Askaryan effect in a dielectric-loaded waveguide. Bunches of 12.16 GeV electrons with total bunch energy of $\sim 10^3-10^4$ GeV were pre-showered in tungsten, and then measured with WR-51 rectangular (12.6 mm by 6.3 mm) waveguide elements loaded with solid alumina ($Al_2 O_3$) bars. In the 5-8 GHz $TE_{10}$ single-mode band determined by the presence of the dielectric in the waveguide, we observed band-limited microwave impulses with amplitude proportional to bunch energy. Signals in different waveguide elements measuring the same shower were used to estimate relative time differences with 2.3 picosecond precision. These measurements establish a basis for using arrays of alumina-loaded waveguide elements, with exceptional radiation hardness, as very high precision timing planes for high-energy physics detectors.

Design of a CPW fed compact bow‐tie microstrip antenna with versatile frequency tunability

A compact coplanar waveguide (CPW) fed frequency reconfigurable bow-tie microstrip antenna is proposed and experimentally verified which can be tuned at different bands between 1.94 and 3.27 GHz in single-band and dual-band modes. Two slots are carefully introduced on the ground plane of the antenna where two active varactor diodes are placed to vary its fundamental mode of radiation by variation of capacitance. To validate the antenna design, a fully functional prototype is fabricated and measured which ensures that the device can be operated at different frequencies of 2.02, 2.19 and 2.37 GHz with 35.9, 30.8 and 24.6% of impedance bandwidth, respectively, in the single-band mode. In dual-band reconfigurability mode, the resonant frequency of the antenna can be varied at 2.08, 2.17 and 2.3 GHz with a higher mode band within 2.7 and 3.3 GHz. The antenna shows maximum gain of 1.33 dB with 96.9% efficiency and 1.5 dB with 95.4% efficiency for single-band and dual-band reconfigurability mode, respectively. More importantly, the antenna has a compact dimension (0.31λ×0.32λ×0.0103λ at 1.94 GHz) and it produces symmetrical monopole type radiation pattern at all tunable bands.

Multi-Reconfigurable Band-Notched Coplanar Waveguide-Fed Slot Antenna

This paper proposes an antenna design concept to achieve a multi-reconfigurable band-notch antenna by using a set of microswitches. The proposed idea was proved by the design of the coplanar waveguide (CPW)-fed slot antenna. The sample design gives a wideband antenna the impedance bandwidth of which covers the frequency ranged from 1.9 GHz to 6.55 GHz. The antenna could be configured to work either in single-band mode or in one of the defined dual-band modes.

An EH0-Mode Microstrip Leaky-Wave Antenna With Periodical Loading of Shorting Pins

In this paper, a novel class of microstrip leaky-wave antennas (MLWAs) under the operation of the fundamental EH0-mode in a microstrip line (MSL) is presented. The leaky-wave radiation is realized by periodically loading a set of shorting pins in the central plane along the longitudinal direction. Due to the inductive effect of these shorting pins, the phase constant of this pin-loaded MSL is reduced below its free-space counterpart so as to create a fast-wave frequency region for leaky-wave propagation and radiation. Compared with its counterpart higher order EH1- or EH2-mode MLWAs, the strip width of this EH0-mode MLWA can be freely designed with unspecified or narrow strip width. Our extensive investigations are then carried out to demonstrate its inductive-loaded fast-wave mechanism and distinctive characteristics, such as narrower strip width, low cutoff frequency, wide single-mode band, and controllable leakage constant in the fast-wave region. In final, two antenna prototypes with strip widths of 4.0 and 7.5 mm are designed, fabricated, and measured, with simulated and measured results in good agreement, validating the proposed pin-loaded technique for designs of EH0-mode MLWAs.

Comparative study of the pentamodal property of four potential pentamode microstructures

In this paper, a numerical comparative study is presented on the pentamodal property of four potential pentamode microstructures (three based on simple cubic and one on body-centered cubic structures) based on phonon band calculations. The finite-element method is employed to calculate the band structures, and the two essential factors of the ratio of bulk modulus B to shear modulus G and the single-mode band gap (SBG) are analyzed to quantitatively evaluate the pentamodal property. The results show that all four structures possess a higher B/G ratio than traditional materials. One of the simple cubic structures exhibits the incomplete SBG, while the three other structures exhibit complete SBG to decouple the compression and shear waves in all propagation directions. Further parametric analyses are presented investigating the effects of geometrical and material parameters on the pentamodal property of these structures. This study provides guidelines for the future design of novel pentamode microstructures possessing a high B/G ratio and a low-frequency broadband SBG.

Compact Frequency-Reconfigurable Slot Antenna for Wireless Applications

A compact frequency-reconfigurable slot antenna for LTE (2.3 GHz), AMT-fixed service (4.5 GHz), and WLAN (5.8 GHz) applications is proposed in this letter. A U-shaped slot with short ends and an L-shaped slot with open ends are etched in the ground plane to realize dual-band operation. By inserting two p-i-n diodes inside the slots, easy reconfigurability of three frequency bands over a frequency ratio of 2.62:1 can be achieved. In order to reduce the cross polarization of the antenna, another L-shaped slot is introduced symmetrically. Compared to the conventional reconfigurable slot antenna, the size of the antenna is reduced by 32.5%. Simulated and measured results show that the antenna can switch between two single-band modes (2.3 and 5.8 GHz) and two dual-band modes (2.3/4.5 and 4.5/5.8 GHz). Also, stable radiation patterns are obtained.

A Compact Frequency-Reconfigurable Dielectric Resonator Antenna for LTE/WWAN and WLAN Applications

A compact frequency-reconfigurable dielectric resonator antenna (DRA) for LTE/WWAN and WLAN applications is investigated and presented. The proposed antenna provides the frequency tuning between 1.60 and 2.71 GHz. The design consists of four identical rectangular dielectric resonators with permittivity of 10 each and three p-i-n diode switches that are located on the feedline network between each of two dielectric resonators. The proposed antenna size is $20 \times 36 \times 5.57~\hbox{mm}^3$ , which is suitable for mobile devices. The measurement and simulation results are applied to demonstrate the performance of the proposed antenna. From the measured results, it is found that the proposed antenna with acceptable performance provides four single-band modes with the impedance bandwidths of 17%, 11%, 14%, and 6%.

Slot dipole antenna with single‐ and dual‐band tuning characteristic

A slot dipole antenna with a reconfigurable operating frequency is presented. The antenna comprises two pairs of slot arms. Each arm incorporates a number of varactor diodes. The antenna is capable of operating in single-band or dual-band mode. In each case, the location of these bands can be altered by varying the voltage applied to the varactor diodes. The antenna can be tuned over a wide frequency range, namely 1.5-4.5 GHz (i.e. a ratio of 3:1). The antenna is potentially useful for cognitive radio application, particularly in a small base station or access point terminal.

Design and Parametric Analysis of a Dual-Band Frequency Reconfigurable Planar Dipole Using a Dual-Band Artificial Ground Plane

ABSTRACTThis paper presents the design of dual-band frequency reconfigurable fork shape planar dipole in the industrial, scientific and medical (ISM) band (2.4 and 5.2 GHz). The proposed antenna can be used for wireless local area network (WLAN) applications. Antenna operates in dual-band as well as single-band mode depending on switching combination. The proposed antenna gives bandwidth of 12.5% and 6.7% for 2.4 GHz and 5.2 GHz, respectively, in dual-band mode while 15.5% for 2.4 GHz in single-band mode. The performance of the antenna is analysed with a ground-free substrate and traditional perfect electric conductor (PEC) ground plane. The same antenna is mounted on a dual-band slotted mushroom-type electromagnetic bandgap (EBG) surface which improves the return loss of the antenna in both bands by –25 dB w. r. t. the PEC-based dipole antenna. The proposed antenna can be used in WLAN applications. The simulations were carried out in SEMCAD and CST MWS.

A Concurrent $Ku/K/Ka$ Tri-Band Distributed Power Amplifier With Negative-Resistance Active Notch Using SiGe BiCMOS Process

A new tri-band power amplifier (PA) on a 0.18- μm SiGe BiCMOS process, operating concurrently in Ku-, K-, and Ka-band, is presented. The concurrent tri-band PA design is based on the distributed amplifier structure with capacitive coupling to enable large device size, while maintaining wide bandwidth, gain cells with the enhanced-gain peaking inductor, and negative-resistance active notch filters for improved tri-band gain response. The concurrent tri-band PA exhibits measured small-signal gain around 15.4, 14.7, and 12.3 dB in the low band (10-19 GHz), midband (23-29 GHz), and high band (33-40 GHz), respectively. In the single-band mode, the PA has maximum output powers of 15, 13.3, and 13.8 dBm at 15, 25, and 35 GHz, respectively. When the PA is operated in dual-band mode, it has maximum output powers of 11.4/8.2 dBm at 15/25 GHz, 13.3/3 dBm at 15/35 GHz, and 8.7/6.7 dBm at 25/35 GHz. In the tri-band mode, it exhibits 8.8/5.4/3.8-dBm maximum output power at 15/25/35 GHz. The concurrent tri-band PA exhibits relatively flat responses in gain and output power across its three frequency bands and good matching up to 40 GHz.

Inductor‐less envelope modulated radio frequency power amplifier using stacked amplifiers and envelope shaping

An envelope modulated radio frequency (RF) power amplifier (PA) is presented using a `stacked amplifiers' modulator. The modulator combines the efficiency of class G with the convenience of a charge pump. Since it is a single band modulator, no large inductors or transformers are required. A two level prototype has been developed and tested with a 7.5 dB peak-to-average power ratio 1.4 MHz bandwidth long term evolution (LTE) signal. Envelope shaping was used to improve linearity. Individually the modulator achieved between 54 and 60% efficiency, dependant on the envelope shaping function. When combined with a suitable class E PA, 40% DC to RF efficiency was achieved at 1.38 W output power with the 1.4 MHz LTE signal.

New Technique for Synthesizing Concurrent Dual-Band Impedance-Matching Filtering Networks and ${\hbox{0.18-}}\mu{\hbox {m}}$ SiGe BiCMOS 25.5/37-GHz Concurrent Dual-Band Power Amplifier

New technique for synthesizing concurrent dual-band impedance-matching filtering networks is presented. The technique enables the design of concurrent dual-band impedance-matching filtering networks that provide not only simultaneous matching of two arbitrary loads to two arbitrary sources at two different frequencies, but also dual-bandpass filtering response capable of suppressing unwanted signals like the harmonics and inter-modulation products in nonlinear circuits, such as power amplifiers (PAs). A new 0.18-μm SiGe BiCMOS concurrent dual-band PA was designed based on the developed dual-band matching filtering technique around 25.5 and 37 GHz, which works in the concurrent dual-band mode (25.5 and 37 GHz), as well as single-band mode (25.5 or 37 GHz). The measured results show that, in the single-band mode, the dual-band PA exhibits gain of 21.4 and 17 dB, maximum output power of 16 and 13 dBm, and maximum power-added efficiency (PAE) of 10.6% and 4.9% at 25.5 and 37 GHz, respectively. In the dual-band mode, the maximum output power is 13 and 9.5 dBm at 25.5 and 37 GHz, respectively, and the total maximum PAE is 7.1%. The designed concurrent dual-band PA has a chip size of 1.3×0.68 mm2 and consumes a dc current of 120 mA from a 3-V supply voltage.

Frequency-Reconfigurable Rectangular Dielectric Resonator Antenna

A coplanar waveguide (CPW) reconfigurable dielectric resonator antenna (DRA) is presented and investigated. The DRA is capable of frequency tuning at three different frequency bands between 3.45 and 6.77 GHz. The overall size of the antenna is 50 × 57 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The dielectric material is a rectangular block of ceramic with a permittivity of 15. Two switches, implemented using p-i-n diodes, are located on the lines of a feed network that is connected to the dielectric element. Single-band modes with impedance bandwidths of 8% and 16% are achieved by switching “on” one of three connecting feedline networks, whereas a wide band, with an impedance bandwidth of 65%, is achieved by switching “on” two connecting lines. Frequencies in the single band can be independently controlled using switch positions without affecting the wideband mode. The prototype has a low profile with a dielectric resonator thickness of 4 mm. The characteristics of this antenna were studied, and good agreement was found between the numerical and measured results.

Reconfigurable tri-band H-shaped antenna with frequency selectivity feature for compact wireless communication systems

This study presents an H-shaped reconfigurable antenna for wireless applications. The antenna consists of an H-shape radiator and a CPW printed on a circuit board and a varactor diode connecting the upper and lower arms of the H-shape radiator for reconfigurability. The uniqueness of the antenna lies on the ability to select the operating mode and frequencies electronically using a varactor diode. By selecting the DC-bias voltages of 11.5, 10 and 8 V across the varactor diode, which in turn selects the corresponding varactor capacitances of 2, 4 and 6 pF, the antenna can be controlled to operate in three different modes, namely a single-band mode to cover the GSM1900, a dual-band mode at 1.88 and 2.4 GHz to cover the GSM1900 and Bluetooth/WLAN, respectively and a tri-band mode at 1.57, 1.88 and 2.4 GHz to cover the GSM1900, WLAN and GPS, respectively. Furthermore, by varying the varactor capacitance from 7 to 13 pF, the GPS and WLAN bands can be tuned by 11.44% (1.57–1.4 GHz) and 6.46% (2.4–2.25 GHz), respectively, yet keeping the 1.88-GHz band unchanged. Detailed studies on the antenna&apos;s performance are carried out to investigate the behaviour of the antenna at each resonant frequency in each operating mode.

Concurrent dual-band SiGe HBT power amplifier for Wireless applications

This paper presents an investigation of a concurrent low-cost dual-band power amplifier (PA) fabricated in SiGe technology, able to simultaneously operate at two frequencies of 2.45 and 3.5-GHz, including an evaluation of its system level performance potentiality. Taking into account the technology novelty and the lack of device characterization and modeling, a hybrid (MIC) approach has been adopted both for a fast prototyping of the PA and for the evaluation of the device potentiality based on an extensive linear and nonlinear characterization. The comparison of PA performance in single-band or concurrent mode operation will be presented. In particular, the measured PA prototype shows an output power of 17.2 and 17-dBm at a 1-dB compression point, at 2.45 and 3.5-GHz, respectively, for CW single-mode operation, with a power added efficiency around 20%. System-level analysis predicts that, when the PA is operated under the 20-MHz Orthogonal Frequency-Division Multiplexing (OFDM) concurrent signals, the maximum output power levels to maintain the Error Vector Magnitude (EVM) within 5% are 11 and 3.5-dBm at 2.45 and 3.5-GHz, respectively. Moreover, new concepts and possible new system architectures for the development of the next generation of the multi-band transceiver front-end will be provided with an extensive system-level evaluation of the amplifier.

From device characterization to system level analysis of dual band PA design in SiGe technology

In this article, the design of a dual-band PA developed in SiGe HBT technology and its system level investigation are presented. Starting from an extensive nonlinear characterization at the device level, by which the optimum load conditions was inferred, an optimized amplifier capable to operate simultaneously at 2.45 and 3.5 GHz was designed. The designed amplifier exhibits in single-band mode operation 9.3 dBm and 13.4 dBm output power (1 dB compression point) at 2.45 GHz and 3.5 GHz, respectively. When working under simultaneous channel amplifications, an higher reduction of the 1 dB compression point at 3.5 GHz, compared with the one at 2.45 GHz, is observed; this reflects in a more significant degradations of system level performance such as the error vector magnitude. The investigation provided in this article and the conclusions suggest new concepts and possible new system architectures for the development of the next generation of multi-band transceiver front-end

Design of a novel wideband single-mode waveguide in a photonic crystal slab structure

We propose a novel photonic crystal slab waveguide that provides a single-mode band with large bandwidth. The proposed waveguide is obtained by introducing a line defect in a triangular lattice of air holes in a dielectric slab. This line defect consists of holes which are not located in the original lattice points. The plane wave expansion (PWE) method is used to extract the band diagram of guiding modes and based on the results, photonic crystal holes in the defect row and its adjacent rows are modified to maximize the waveguide bandwidth. We show that using the proposed structure, a single-mode bandwidth of 17% can be achieved.

A method for estimating the power spectral density of an information signal for evaluation of formant intelligibility of speech under lumped interference conditions

Based on the coherency function properties, a new method for estimating the power spectral density of an information signal in the presence of lumped interference is suggested. The paper includes results of instrumental calculation of articulation characteristics when reception of signals with single-band modulation occurs in the presence of lumped interference modulated in phase by Gaussian random process.