InGaAs microwave switch transistors for phase shifter circuits

A new InGaAs insulated-gate FET (IGFET) with 1 μm gate length and three different gate widths has been designed, fabricated and characterized as switch devices for microwave control applications in phase shifter circuits. The devices employed a plasma deposited silicon dioxide gate insulator and had multiple air bridged source regions. The details of the DC current-voltage (I-V) characteristics and small signal S-parameter measurements up to 20 GHz are presented. The switch IGFET's had a drain saturation current density of 300 mA/mm gate width with breakdown voltages of higher than 35 V. An insertion loss of 1.0, 0.6, and 0.4 dB at 10 GHz and 1.4, 0.8, and 0.4 dB at 20 GHz have been measured for the 300, 600, and 1200 μm gate width IGFET's, respectively. Equivalent circuit models fitted to the measured S-parameters for IGFET's yielded on-state resistances from 10.7 to 3.3 Ω, off-state resistances from 734.4 to 186.8 R and off-state capacitances from 0.084 to 0.3 pF as the gate width is increased from 300 to 1200 μm The simulation results using IGFET models for the phase shifter circuits indicated a maximum phase error of 0.11°, 0.26°, and 0.479 with 0.74, 0.96, and 1.49 dB maximum insertion loss and greater than 33, 26, and 19 dB return loss for the 11.25°, 22.5°, and 45° phase bits, respectively, over the 9.5-10.5 GHz frequency band     

Millimetre-wave wideband reflection-type CPW MMIC phase shifter

A reflection-type coplanar waveguide (CPW) phase shifter fabricated using a standard monolithic microwave integrated circuit (MMIC) process is presented. Air-gap overlay CPW couplers were employed for wideband 3 dB coupling and low loss at millimetre wave. The two-stage cascaded analogue phase shifter showed insertion losses of 6.9 ± 1.6 dB, return losses > 10 dB, and maximum rms phase error of +5.5° for the relative phase shift from -20° to 135°, over a wideband 27 to 47 GHz     

A new high performance phase shifter using BaxSr1-xTiO3 thin films

In this paper, a new device topology has been proposed to implement parallel plate capacitors using Ba_xSr_1-xTiO₃ (BST) thin films. The device layout utilizes a single parallel capacitor and minimizes conductor losses in the base electrode. The new design simplifies the monolithic process and overcomes the problems associated with electrode patterning. An X-band 180° phase shifter has been implemented using the new device design. The circuit provided 240° phase shift with an insertion loss of only 3 dB at 10 GHz at room temperature. We have shown a figure of merit 93°/dB at 6.3 GHz and 87°/dB at 8.5 GHz. To our knowledge, these are the best figure of merit results reported in the literature for distributed phase shifters implemented using BST films at room temperature     

An MMIC active phase shifter using a variable resonant circuit [andMESFETs]

This paper describes a monolithic-microwave integrated-circuit (MMIC) active phase shifter using a variable resonant circuit with a large amount of variable phase. We first propose a novel active phase-shifter configuration that uses a variable resonant circuit with second-order all-pass network characteristics. Phase can be changed with a constant amplitude by varying the capacitance or the inductance of the resonant circuit. Next, an experimental MMIC active phase shifter with input active matching is presented. A phase shift of over 100° and an insertion loss of 4±1 dB are obtained from 2.2 to 2.8 GHz. The chip size is less than 1.0 mm². Finally, an experimental 360° MMIC active phase shifter is presented. Over the bandwidth of 40 MHz at 2.44 GHz, the insertion gain is 2.0±0.7 dB and the phase error is within ±4° when measured in 30° steps     

A Novel Miniature 1–22 GHz 90° MMIC Phase Shifter with Microstrip Radial Stubs

A novel miniature ultra wide bandwidth 90 monolithic microwave integrated circuit phase shifter with microstrip radial stubs operated from 1 to 22 GHz is presented. The phase shifter exhibits a high performance. Within the whole bandwidth from 1 to 22 GHz, the phase error of the phase shifter is less than 3deg, the return losses of the different phase shift states are more than 14 dB, the insertion loss of all phase shift states are within 3.3plusmn0.5 dB. The chip size of this phase shifter is 1.4 mm times 1.8 mm times 0.1 mm. The proposed phase shifter can be compatible with different polarity control signals without the need of drivers and can also be compatible with either analogue or digital control signals.     

Optimum field theory design of broad-band E-plane branchguide phase shifters and 180° couplers

Optimum rectangular waveguide E-plane branch guide phase shifters and 180° branch guide couplers are designed with the rigorous method of field expansion into normalized eigenmodes. The design includes both the higher order mode interaction between the step discontinuities and the finite step and branch heights. The phase shifter design applies the Schiffman principle to branch guide couplers where two ports are short-circuited. The 180° coupler design combines the advantage of the broadband potential of multiple-branch couplers with the low-insertion-loss qualities of E-plane stub-loaded phase shifters. A computer-optimized phase shifter prototype for the waveguide Ku-band (12-18 GHz) shows a 90°±1° differential phase shift with reference to an empty waveguide within about 23% bandwidth. Five-branch three-stub coupler prototypes, designed for 3±0.2 dB coupling, for the waveguide Ku- and Ka-bands (26-40 GHz) achieve a 180°±1° differential phase shift at the output ports within about 19% bandwidth, as well as more than 30 dB isolation and return loss. The theory is verified by measured results     

A Ku‐Band 5‐Bit Phase Shifter Using Compensation Resistors for Reducing the Insertion Loss Variation

This paper describes the performance of a Ku‐band 5‐bit monolithic phase shifter with metal semiconductor field effect transistor (MESFET) switches and the implementation of a ceramic packaged phase shifter for phase array antennas. Using compensation resistors reduced the insertion loss variation of the phase shifter. Measurement of the 5‐bit phase shifter with a monolithic microwave integrated circuit demonstrated a phase error of less than 7.5° root‐mean‐square (RMS) and an insertion loss variation of less than 0.9 dB RMS for 13 to 15 GHz. For all 32 states of the developed 5‐bit phase shifter, the insertion losses were 8.2 ± 1.4 dB, the input return losses were higher than 7.7 dB, and the output return losses were higher than 6.8 dB for 13 to 15 GHz. The chip size of the 5‐bit monolithic phase shifter with a digital circuit for controlling all five bits was 2.35 mm × 1.65 mm. The packaged phase shifter demonstrated a phase error of less than 11.3° RMS, measured insertion losses of 12.2 ± 2.2 dB, and an insertion loss variation of 1.0 dB RMS for 13 to 15 GHz. For all 32 states, the input return losses were higher than 5.0 dB and the output return losses were higher than 6.2 dB for 13 to 15 GHz. The size of the packaged phase shifter was 7.20 mm × 6.20 mm.     

Design and performance of a Ka-band monolithic phase shifterutilizing nonresonant FET switches

This paper describes design consideration and performance of a Ka-band monolithic phase shifter utilizing nonresonant FET switches. The switches show broad-band on/off characteristics up to 60 GHz without using inductors; thus, robust circuit design is possible for a switched-line phase shifter. To determine circuit topology, we introduce a schematic design approach. As a result, desired phase shift as well as good matching characteristics can be realized. The developed 4-bit monolithic phase shifter demonstrates an overall phase deviation less than 5° rms and an insertion loss variation less than 0.65 dB rms from 33 to 35 GHz. For all 16 states, the insertion loss is measured to be 13.1±1.1 dB and the VSWR is less than 1.6. The chip size of the monolithic phase shifter is 2.5 mm×2.2 mm     

A low-cost 8 to 26.5 GHz phased array antenna using a piezoelectrictransducer controlled phase shifter

A new phased array antenna of wide bandwidth and good beam scanning angle has been developed using a low cost multiline phase shifter controlled by a piezoelectric transducer (PET) and a stripline fed Vivaldi antenna array. The multiline progressive PET phase shifter has a low perturbation loss of less than 2 dB and a total loss of less than 4 dB up to 40 GHz with a maximum phase shift of 480°. The proposed phased array antenna consists of four E- or H-plane Vivaldi antennas, a PET phase shifter, and a power divider. The phased array shows a wide beam scanning capability of ±27° over a wide bandwidth from 8 to 26.5 GHz covering X, Ku, and K bands     

A wide range analog MMIC attenuator with integral 180° phaseshifter

A circuit topology is discussed for achieving a wide-range analog attenuator in MMIC form using enhancement mode FET's by combining it with a 90° phase shift network. By switching the phase shift network between a 90° phase lead high-pass structure and a 90° phase lag low-pass structure, a dual-purpose circuit is formed comprising both a variable attenuation and 180° phase shift function. The approach requires only a single control voltage for the attenuator and achieves an attenuation range of over 30 dB in L-band with less than 10° of phase imbalance over the range. In the low-loss state, the phase shifter achieves a 10° phase balance over a 250 MHz bandwidth with less than 0.3 dB of amplitude imbalance     

High Tc superconducting three-pole parallel-coupled bandpass filters made from laser ablated YBa2Cu3O7 − δ thin films

We have investigated three-pole parallel-coupled bandpass filters with fractional bandwidths of about 6% and 3% at a center frequency of 10.5 GHz utilizing high T_c superconducting YBa₂Cu₃O_{7 − δ} thin films. The films were deposited on LaAlO₃ substrates by pulsed laser ablation. Microwave responses of the filters were measured as a function of temperature and input power. The performance of the 3% bandwidth filter exhibits low insertion losses of about 0.48 dB and 0.79 dB at 20 K and 77 K, respectively. The insertion loss in the 6% bandwidth filter was 0.96 dB at 77 K. Both filters showed return losses better than 15 dB. High T_c superconducting bandpass filters showed good reproducibility. They were also compared with equivalent gold filters which showed insertion losses of more than 8 dB at 77 K.     

Optimum design of waveguide E-plane stub-loaded phaseshifters

Broadband low-insertion-loss E-plane stub-loaded rectangular waveguide phase shifters are designed with the method of field expansion into normalized eigenmodes, which includes higher-order mode interaction between the step discontinuities. Computer-optimized three-stub prototypes of 90° differential phase shift with reference to an empty waveguide of appropriate length, designed for R140-band (12.4-18 GHz) and R320-band (26.5-40 GHz) waveguides, achieve typically ±0.5° phase shift deviation within about 20% bandwidth. For two-stub designs, the corresponding values are about +2.5°/-1° and 17%. Both designs achieve minimum return loss of 30 dB. The theory is verified by measurements of a compact R120-band (10-15 GHz) waveguide phase shifter design example milled from a solid block, showing measured insertion loss of about 0.1 dB and about +2.5°/-0.5° phase error between 10.7 and 12.7 GHz     

A 10- to 21-GHz, low-cost, multifrequency, and full-duplexphased-array antenna system

This paper presents a novel phased-array antenna system with multifrequency, full-duplex operation, and wide-beam scanning. The system consists of a wideband power divider, a low-loss and low-cost multiline phase shifter controlled by dual piezoelectric transducers (PETS), a four-channel multiplexer, microwave monolithic integrated circuit (MMIC) amplifiers, and a stripline-fed Vivaldi antenna array. The multiline PET phase shifter has a low perturbation loss of less than 2 dB and a total loss of less than 4 dB up to 40 GHz, with a maximum phase shift of 650°. Using dual-aligned PETS for bidirectional phase shifting results in wide scan angles of 38.6°, 37.6°, 43°, and 40° for the four channels at 10, 12, 19, and 21 GHz, respectively. The four-channel diplexer demonstrates low insertion loss with high isolation between channels. The new multifrequency phased-array system provides wide-beam scanning and full-duplex capability using a simple, low-cost architecture. The system can be used for applications in mobile satellite communications     

11.25°毫米波数字移相器的设计

设计了一种Ka波段11.25°数字移相器。采用一前一后加载支线的方式,在Ka波段内研制出11.25°数字移相器。该移相器在30～31GHz工作频带内,驻波比小于1.65,插入损耗小于3dB,固定相移11.25°,相位精度达到±3°。     

Flat spectral response arrayed-waveguide grating multiplexer withparabolic waveguide horns

An eight-channel flat spectral response arrayed-waveguide grating multiplexer with parabolic waveguide horns has been fabricated on a planar lightwave circuit (PLC). A double-peaked intensity distribution is formed at the slab interface by the parabolic waveguide horn. A 1 dB bandwidth of 98 GHz, 3 dB bandwidth of 124 GHz and 20 dB bandwidth of 196 GHz are obtained for 200 GHz channel spacing. The crosstalk to neighbouring channels is less than -27 dB and the on-chip insertion losses range from 6.1 to 6.4 dB, respectively     

A Full-360° Reflection-Type Phase Shifter With Constant Insertion Loss

A new reflection-type phase shifter with a full 360deg relative phase shift range and constant insertion loss is presented. This feature is obtained by incorporating a new cascaded connection of varactors into the impedance-transforming quadrature coupler. The required reactance variation of a varactor can be reduced by controlling the impedance ratio of the quadrature coupler. The implemented phase shifter achieves a measured maximal relative phase shift of 407deg, an averaged insertion loss of 4.4 dB and return losses better than 19 dB at 2 GHz. The insertion-loss variation is within plusmn0.1 and plusmn0.2 dB over the 360deg and 407deg relative phase shift tuning range, respectively.     

Ultra compact, low loss, varactor tuned phase shifter MMIC atC-band

This paper presents a high yield, ultra compact, low loss phase shifter MMIC, realized with a commercial 0.6 μm GaAs MESFET process. Phase shift is enabled by varying the varactor capacitances of the lumped element equivalent of a transmission line. Continuously adjustable phase control over 90° is achieved from 4 GHz up to 6 GHz, with a loss of less than 2.2 dB. At 5.2 GHz, a loss of 1.2 dB and a loss variation of ±0.5 dB is measured. Phase and loss variations for several circuits from different wafers are within ±1° and ±0.1 dB, respectively, indicating low dependences on process variations. The phase shifter requires a circuit size of only 0.2 mm², which to our knowledge is the smallest size for a continuously adjustable passive phase shifter with comparable performance, reported to date     

Fin-line Pin diode BPSK and QPSK modulators

A low insertion lose fin-line PIN diode phase shifter is presented. 90° and 180° phase shifters are realized respectively. Phase error less than 5° and bandwidth 3 GHz at Ka band are achieved. The insertion loss is better than 0.5dB. The BPSK and QPSK modulators consisting of this phase shifter and fin-line coupler are also given. The circuits and results are given.     

一种S频段反射型可调模拟移相器的设计

设计了一种应用于S频段卫星通信相控阵系统的反射型可调模拟移相器。该移相器利用三分支线定向耦合器扩展了带宽,改善了工作频段内驻波;采用传输线和变容二极管构成的L型反射负载扩大了相移量。测试结果表明,在上行频段1.98～2.01 GHz内,相移量达到191°±1°,在下行频段2.17～2.2 GHz内,相移量达到186°±0.1°;插入损耗优于3.3 dB且插入损耗波动小于1 dB,回波损耗在整个电压调谐范围内均大于20 dB。该移相器结构简单、便于调节且价格低廉,在卫星通信领域有一定的应用价值。     

2×2 optical waveguide switch with bow-tie electrode based oncarrier-injection total internal reflection in SiGe alloy

Based on the total internal reflection and the plasma dispersion effect of SiGe alloy, a 2×2 intersectional rib optical waveguide switch with bow-tie electrode has been proposed and fabricated for the wavelength of 1.3-μm operation. The thickness of the SiGe layer is 2.6 μm and the width is 9 μm. The branch angle of the switch is 2° and the bow-tie angle is 1.5°. The on-state crosstalk is -19.6 dB, the off-state extinction ratio is 38.5 dB and the off-state insertion loss is less than 1.70 dB. The switching time is about 180 ns