Reflection-type Phase Shifter Research Articles

Corrections to "An ultra-broad-band reflection-type phase-shifter MMIC with series and parallel LC circuits" [Dec 01 2446-2452

The above-named article [ibid., vol. 49, no. 12, pp. 2446?2452, Dec. 2001] analyzed an ultra-broad-band reflection-type phase shifter. This phase shifter consists of a 3-dB hybrid coupler and a pair of reflective terminating circuits that switch two states of ideal parallel and series circuits. The authors have extracted the circuit elements of parallel and series as functions of center frequency and desired phase difference to obtain broadband characteristics. Two reflecting terminating circuit monolithic microwave integrated circuits (MMICs) with 90 and 180 phase shifts were designed and fabricated at the conclusion of the article. We respectfully express what seems to be error. For circuit topology shown in Fig. 2, the authors extracted circuit element values (eqs. (30)-(33)) to achieve broadband characteristics. These formulas are the most important part of the article, but they are incorrect. The correct inductive and capacitance circuit elements and given here.

Compact Tunable Reflection Phase Shifters Using Short Section of Coupled Lines

In the design of reflection-type phase shifters, the coupler that represents the shifter's backbone is usually assumed to be a quarter-wavelength 3-dB coupler. In this paper, a derived theoretical model shows that, for certain values for the odd- and even-mode impedances, a coupled structure with a length that is less than one tenth of a wavelength is sufficient to build a high-performance reflection phase shifter. The presented analysis indicates that reflection phase shifters can be designed with a more compact size and larger phase range compared with the conventional method of using a quarter-wavelength 3-dB coupler. However, the required odd-mode impedance in the proposed design is low (≈10 Ω) , whereas the required even-mode impedance is high (≈200 Ω). To realize those impedances when using parallel-coupled lines, slotted ground and shunt chip capacitor are used. The proposed design is supported by full-wave electromagnetic simulations and measurements. The simulated results show that 0.085λ coupled structure achieves 255° phase range across 36% fractional bandwidth with less than 1-dB insertion loss and more than 10-dB return loss. In another design, a full-cycle phase range is obtained with less than 1.5-dB insertion loss across the same band by using two 0.076λ coupled sections. A manufactured prototype for a full-cycle phase range validates the simulation results and, thus, the proposed method.

Ka-Band Phased Array Antenna for High-Data-Rate SATCOM

The general issue of this letter deals with the design of a phased array antenna for high-data-rate SATCOM. A final demonstrator antenna could be installed on an unmanned aerial vehicle (UAV) to communicate with a satellite in Ka-band. First, a compact reflection-type phase shifter is designed and realized. Second, the conception of a phased array antenna prototype is detailed. Third, a new calibration method is involved that can provide the bias voltage to be applied to each phase shifter in order to scan the beam in the desired direction.

Tunable Microwave Phase Shifters Using LTCC Technology with Integrated BST Thick Films

Low temperature co‐fired ceramic (LTCC) reflection and delay line type microwave phase shifters utilizing completely integrated barium strontium titanate (BST) varactors are investigated. Dielectric properties of the screen printed BST paste in 1–8 GHz frequency range are presented. Sintering temperature and time were varied and their effect on the dielectric properties of the film was studied. Phase shifters were sintered at 875°C for 25 min in line with a standard LTCC sintering profile. The relative phase shift of the reflection and delay line type phase shifters were found to be 5 and 11.5° at 2.5 GHz with applied bias field strength of 8 V/μm, respectively.

High Resolution Tunable MEMS Phase Shifters for Radar Phased Array Antenna

The paper proposes a high resolution tunable MicroElectroMechanical Systems (MEMS) phase shifters for radar phased array antenna to steer the beam. Two phase shifters are considered the first is a switched line phase shifter; the second is a reflection type phase shifter. The resolution of the designed phase shifters is two degree phase shift using 8 bit control circuitry. The proposed circuit is based on dividing the tuning range into coarse and fine tuning sections which change the phase by 30o and 2o steps respectively to achieve the desired phase. A microstrip phase shifters have been designed at 3 GHz suitable for surveillance radar applications. The development of RF MEMS switches over the past years has enabled system designers to consider replacing the GaAs phase shifters with RF MEMS phase shifters. MEMS phase shifter exhibit excellent characteristics, including low insertion loss and low DC power consumption. The designed phase shifters are simulated and tested using Advance Design System circuit simulation package (ADS) and the results demonstratedusing the graphics capability of Matlab Program. The results show that the worst case insertion loss is less than 0.17 dB and 0.05 dB for switched line and reflection type phase shifters respectively. The return loss for the two proposed phase shifters is less than -60 dB.

60 GHz reflection-type phase shifter using 0.13 [micro sign]m CMOS body-floating switches

A two-bit reflection-type phase shifter (RTPS) is fabricated using 0.13 µm CMOS process for 60 GHz operation. The reflective loads in the RTPS are designed to achieve minimal loss with use of shunt switches and body-floating resistors. The measurement shows an average insertion loss of 6.4 dB for four phase states with the worst case loss of 7.7 dB at 60 GHz.

Analysis and design of a new reflection‐type 360° phase shifter with combined switch and varactor

AbstractAnalysis and design of a new 360° reflection type phase shifter is proposed.The new phase shifter uses a switch and one varactor device per reflective load. Equations for the analysis and design of the new phase shifter are presented. A 2.5 GHz phase shifter is fabricated using a varactor diode and a PIN diode per load. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 530–535, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24975

Millimeter-Wave Reflective-Type Phase Shifter in CMOS Technology

The design and measurement of a compact, wide-band reflective-type phase shifter in 90 nm CMOS technology in V-band frequency is presented. This phase shifter has a fractional bandwidth of 26% and an average insertion loss of 6 dB over all phase states. The chip area is only 0.08 mm 2. Measurement results show that the developed phase shifter provides 90° continuous phase shift over the frequency range of 50-65 GHz. The measured return loss is greater than 12 dB at 50 GHz. The output power is linear up to at least 4 dBm input power.

CMOS 기반 BPSK 수신기와 반사형 위상 천이기를 이용한 QPSK 복조기 설계

We propose and demonstrate an I/Q demodulator using four-port BPSK demodulator base on additive mixing and reflection-type phase shifter using hybrid technique. Previously, the conventional I/Q demodulator base on multiplicative or additive mixing method divides I/Q signal path from mixer to parallel-to-serial converter. In this paper, we propose new I/Q demodulator without dividing I/Q baseband signal path. The proposed schematic requires half size in implementation and half power consumption in baseband path compared with the conventional receiver. Also, the proposed receiver eliminates parallel-to-serial converter after data decoding. The proposed circuit has been successfully demodulated a QPSK signal with the L-band carrier frequency and 20 Mbps data rate.

Reflection-type continuously-tunable phase shifter using PZT thin-film capacitors

The design, fabrication and performance of a reflection-type tunable phase shifter based on a lead zirconate titanate (PZT) thin-film process is presented. The phase shifter consists of a coplanar waveguide Lange coupler on high resistivity silicon (HRSi) and two ferroelectric PZT varactors. At 12 GHz, the varactors achieve a capacitance tuning range of 5.5 to 1 along with a phase shift of 86 with bias voltages in the range 0-26 V. Analysis of the losses due to the varactors and the rest of the phase shifter is also presented.

On the use of a Rat-Race Coupler in the Design of a 180° Phase Shifter

This paper investigates the use of a rat-race coupler in designing a reflection-type phase shifter with a 180° differential phase shift. The effects of the design parameters on performance are discussed; reported results demonstrate that bandwidths up to 27% with a phase error of ±2° can be obtained. Experimental results referred to a microstrip implementation on a FR4 substrate are also given.

2.45-GHz CMOS Reflection-Type Phase-Shifter MMICs With Minimal Loss Variation Over Quadrants of Phase-Shift Range

CMOS reflection-type phase shifters with minimal insertion-loss variation over quadrants of phase-shift range are presented. Two performance enhancement techniques are proposed. First, the 3-dB quadrature hybrid is designed with a phase-compensated inductively coupled hybrid. Second, an impedance-transformed pi-resonated varactor network is presented to provide a full 360deg phase range, using a MOSFET varactor with limited reactance variation range. The design considerations and simulation are described. Two experimental 2.45-GHz phase shifters were implemented in 0.18-mum CMOS technology. One has a measured phase-shift range of 120deg with the insertion loss of 5.6 plusmn 1.2 dB in 2.33-2.60 GHz and the other has a phase range larger than 340deg with the insertion loss of 10.6 plusmn 2 dB in 2.44-2.55 GHz. Both chips are extremely compact with sizes of 0.72 and 0.66 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> , respectively, and consume zero dc power.

Novel Design of a 2.5-GHz Fully Integrated CMOS Butler Matrix for Smart-Antenna Systems

This paper presents a novel design of monolithic 2.5-GHz 4times4 Butler matrix in 0.18-mum CMOS technology. To achieve a full integration of smart antenna system monolithically, the proposed Butler matrix is designed with the phase-compensated transformer-based quadrature couplers and reflection-type phase shifters. The measurements show an accurate phase distribution of 45plusmn3deg, 135 plusmn 4deg, -45 plusmn 3deg, and -135 plusmn 4deg with amplitude imbalance less than 1.5 dB. The antenna beamforming capability is also demonstrated by integrating the Butler matrix with a 1 X 4 monopole antenna array. The generated beams are pointing to -45deg, -15deg, 15deg, and 45deg, respectively, with less than 1deg error, which agree very well with the predictions. This Butler matrix consumes no dc power and only occupies the chip area of 1.36 times 1.47 mm2. To our knowledge, this is the first demonstration of the single-chip Butler matrix in CMOS technology.

An Ultra-Compact CMOS Variable Phase Shifter for 2.4-GHz ISM Applications

An ultra-compact monolithic microwave integrated circuit active variable phase shifter is proposed and implemented using CMOS technology. It is a reflective-type phase shifter consisting of a compact three-transistor active circulator and a second-order LC network. The use of an active inductor in the second-order LC network makes this phase shifter all active and ultra compact with a size of only 0.357 including bonding pads. The phase shifter was designed and demonstrated at 2.4 GHz and has a linear and continuously tunable range of 120 across the 2.4-GHz industrial-scientific-medical band.

A Full-360$^{\circ}$ 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.

Design of a Reflection-Type Phase Shifter With Wide Relative Phase Shift and Constant Insertion Loss

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> A reflection-type phase shifter with constant insertion loss over a wide relative phase-shift range is presented. This important feature is attributed to the salient integration of an impedance-transforming quadrature coupler with equalized series-resonated varactors. The impedance-transforming quadrature coupler is used to increase the maximal relative phase shift for a given varactor with a limited capacitance range. When the phase is tuned, the typical large insertion-loss variation of the phase shifter due to the varactor parasitic effect is minimized by shunting the series-resonated varactor with a resistor <formula formulatype="inline"><tex>$R_{p}$</tex></formula>. A set of closed-form equations for predicting the relative phase shift, insertion loss, and insertion-loss variation with respect to the quadrature coupler and varactor parameters is derived. Three phase shifters were implemented with a silicon varactor of a restricted capacitance range of <formula formulatype="inline"><tex>$C_{v,\min}=1.4$</tex> </formula> pF and <formula formulatype="inline"><tex>$C_{v,\max}= 8\ $</tex></formula> pF, wherein the parasitic resistance is close to 2 <formula formulatype="inline"><tex>$\Omega$</tex></formula>. The measured insertion-loss variation is 0.1 dB over the relative phase-shift tuning range of 237<formula formulatype="inline"><tex>$^{\circ}$</tex></formula> at 2 GHz and the return losses are better than 20 dB, excellently agreeing with the theoretical and simulated results. </para>

Reflective-Type Phase Shifters for Multiple-Antenna Transceivers

A 10.5-GHz reflective-type phase shifter (RTPS) using resonant loads with L-match impedance transformation (RLT) is implemented in a 0.25-mum SiGe BiCMOS process. A 2.4-GHz RTPS with RLT loads is also integrated in 0.18-mum CMOS; it employs a negative resistance (NR) technique to reduce the loss by 5.9 dB compared to a conventional design that is also implemented. Several other 2.4-GHz reflective loads are fabricated in 0.18-mum CMOS including a Y-shaped dual RLT (DRLT). A transformation converts it from a Y-shape to a Delta-shape and enables use of the NR technique in an RTPS with DRLT loads, wherein the loss is reduced by 10 dB and the phase shift range is increased to over 360deg.

Design considerations for integrated CMOS reflective-type phase shifters

An analysis of reflective-type phase shifters with transformed single-resonant loads for integrated CMOS phased-array implementations is presented. Several components of the standard lumped-element coupler can be eliminated without significant performance degradation, to allow more compact implementations. It is found that the varactor should be chosen as small as feasible to minimize sensitivity to parasitic resistance. Larger varactors reduce sensitivity to parasitic capacitance, but this can be compensated for in the phase shifter design. A general design procedure for reflective-type phase shifters is given. A phase shifter operating at 2.0 GHz has been designed and implemented in a 0.18 ?m CMOS process using the design procedures outlined, and it occupies an area of 0.75 mm2 and consumes 6.8 mW of power. The measured phase shift range is 308° for a control voltage varying from 0---1.8 V, which to our knowledge is the largest phase shift range of any CMOS reflective-type phase shifter reported to date.

Insertion Loss in Reflection-Type Microwave Phase Shifter Based on Ferroelectric Tunable Capacitor

A tunable capacitor based on a ferroelectric thin film grown on a dielectric substrate is a promising component for reconfigurable and tunable devices for numerous RF and microwave applications such as phase shifters, tunable filters, and tunable matching networks. The goal of this paper is characterization of the insertion loss in a reflection-type microwave phase shifter based on the ferroelectric tunable capacitor. The reflection-type phase shifter based on ferroelectric planar tunable capacitor was designed, manufactured, and tested. Its simulated and measured insertion loss and phase shift are compared. Two loss mechanisms in the phase shifter were distinguished: the loss in the tunable capacitor and the loss in the associated circuitry (metallization and substrate). The properly organized investigations of the dissipation of energy in metallization and dielectric substrate can result in a sufficient improvement of the quality of the devices. As a final result, one may anticipate that the figure-of-merit of a ferroelectric tunable or switchable phase shifter can reach 200 deg/dB

Fabrication and characterisation of barium strontium titanate thick film device structures for microwave applications

Tunable capacitor elements for microwave phase shifter applications have been fabricated by screen printing barium strontium titanate (BST) films on alumina substrates. A Ba 0.70Sr 0.30TiO 3 composition was chosen for the initial devices as it has been shown to exhibit high tunability at room temperature. A vertical capacitor test structure involving a Pt lower electrode, BST film and Ag top electrode has been used throughout the work. The tunability and figure of merit (phase shift/dB of insertion loss) at 2–3 GHz were found to be strongly dependent on the sintering temperature of the BST layers, with properties improving as the sintering temperature was increased. However, for sintering temperatures >1280 °C, the device properties could not be measured, possibly indicating a problem with the lower Pt electrodes. In order to reduce the sintering temperature required for densification, test structures have also been fabricated using other BST compositions to which sintering aids have been added. Finally, a reflection-type phase shifter (RTPS) based on the capacitor test structure and optimised processing conditions is presented with microwave measurements results.