Computer design of broadband lumped component microwave phase shifter amplifiers

Broadband microwave phase shifts can be obtained using two amplifiers with different phase delays. A computer program which modifies circuits, by adding and removing components and nodes as necessary, has designed two amplifiers having a gain phase difference of 90 degrees but otherwise similar performance.<>     

Surface-acoustic-wave phase shifter using electrical depolarisation

An electrically variable phase shifter employing surface acoustic waves is described that uses electrical depolarisation of a poled PZT ceramic. Phase shifting occurs in a depoling region in which an electric field of variable strength opposes the remanent ferroelectric moment, causing a change in the piezoelectric coupling and surface-wave velocity.     

Analysis of broadband microstrip-slotline transitions withmulti-arm stubs

For a compromised design of microstrip-slotline transitions with multi-arm stubs, the relation between the number of arms and the bandwidth is necessary. This issue is examined using a modelling technique based on the equivalent circuit of the transition. The technique is used to analyse two broadband (1-10 GHz and 5-50 GHz) transitions with stubs having different number of arms     

Microwave phase shifter using optical waveguide structure

A microwave phase shifter with an integrated optics structure with high efficiency is discussed. The structure and the performance of the device are discussed. Microwave phase shifting was carried out using the fabricated phase shifter of titanium diffused LiNbO₃ optical waveguides. The measured voltage to obtain halfwave phase shift for a 800 MHz microwave signal was 7.0 V. The input microwave power was 21 dBm, and the detected output microwave power was -24 dBm, so the microwave insertion loss was calculated to be approximately -45 dB. The optical insertion loss of the device was -12 dB     

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.     

Improved analysis of nonreciprocal remanence ferrite phase shifter in grooved waveguide

In this paper, the nodal finite-element method is used to analyze the differential phase shift of a nonreciprocal remanence ferrite phase shifter in a grooved waveguide. Instead of the former twin-slab model, an improved analytical model is adopted, where the effect of every part of a ferrite toroid on the differential phase shift has been considered. This analysis may replace the correcting factor with good agreement with the experimental data. Furthermore, this analysis is employed to investigate the effect of corner chamfering on the figure-of-merit (differential phase shift per decibel insertion loss) of a ferrite phase shifter. The numerical results are found to agree with the experiments in the literatures.     

Linear tunable phase shifter using a left-handed transmission line

We demonstrate a compact, linear, and low loss variation hybrid phase shifter using a left-handed (LH) transmission line. For frequencies from 4.3 to 5.6 GHz, this phase shifter gives a nearly linear phase variation with voltage, with a maximum deviation of /spl plusmn/7.5/spl deg/. Within this frequency range, the maximum insertion loss is 3.6 dB, and the minimum insertion loss is 1.8 dB over a continuously adjustable phase range of more than 125/spl deg/, while minimum return loss is only 10.2 dB. Furthermore, this phase shifter requires only one control line, and it consumes almost no power.     

A precise digital phase shifter using a phase-locked loop

A phase-locked loop containing a voltage-controlled oscillator (v.c.o.) synchronised to a harmonic of its fundamental output frequency may be used to form an attractive digital phase shifter providing low phase error with relatively simple circuitry and control requirements. Phase increments of 2?/n radians are obtained, where n is the order of harmonic used.     

High power linearized RF phase shifter using anti-series diodes

We present the design and development of a new reflection-type phase shifter (RTPS) that uses anti-series diodes to achieve high linear output power. Using this topology, the PS provides a continuous phase shift of 180/spl deg/ at 1.88GHz. The measured 1-dB compressed RF output power (P/sub 1 dB/) available from the PS is greater than 28dBm over the entire phase-control range.     

RF and microwave phase shifter using complementary bias techniques

A novel method for the design of an RF phase shifter using a standard foundry process is described. This phase shift achieves very low and near-constant insertion loss. The proposed method uses `complementary' control techniques to keep variable parasitic resistance in a standard transistor to a minimum. Using an only single stage reflection configuration which employs N varactor diodes as a reflection terminator and M varactor diodes, a minimum insertion loss variation can be obtained. The technique is verified by measurement when N=M=1     

Microbend fiber-optic phase shifter

The use of spatially periodic microbend transducers to produce phase shift in single-mode fibers has been investigaed. Phase shift of32deg/mum²of transducer displacement per centimeter of trans-3.7deg/mum². cm for a 1023-μm peroid. Phase shifts as large as 560°/cm of transducer length were obtained with the shorter period transducer. These results are compared with predictions based on coupled-mode theory.     

Monolithic surface-acoustic-wave phase shifter

A monolithic surface-acoustic-wave phase shifter is described. The device consists of a distributed Schottky-barrier varactor junction capable of varying the electrical boundary conditions seen by a surface acoustic wave propagating on a piezoelectric medium. Almost 180° of phase shift is achieved in 55 acoustic wavelengths of interaction region at 54 MHz.     

Broadband 180/spl deg/ bit phase shifter using a /spl lambda//2 coupled line and parallel /spl lambda//8 stubs

In this paper, a broadband 180/spl deg/ bit phase shifter using a new switched-network was presented. The new network is composed of a /spl lambda//2 coupled line and parallel /spl lambda//8 open and short stubs, which are shunted at the edge points of a coupled line, respectively. According to a desired phase shift, it provides a controllable phase dispersive characteristic by the proper determination of Z/sub m/,Z/sub s/, and R values. The 180/spl deg/ bit phase shifter operated at 3 GHz was fabricated and experimented using design graphs which provide the required Z/sub m/,Z/sub s/ values, and I/O match and phase bandwidths. The experimental performances showed broadband characteristics.     

Woodpile EBG phase shifter

A phase shifter in an alumina woodpile electromagnetic bandgap (EBG) defect waveguide that operates at microwave frequencies is demonstrated. The phase shift is introduced by sequentially adding low dielectric constant rods to the voids directly above the defect waveguide. The addition of the extra rods creates selected phase delay without significantly affecting the transmission performance of the woodpile waveguide. Measured and computed results in Ku-band are presented to confirm the performance of the device     

Balanced distributed-element phase shifter

We present a balanced distributed-element phase shifter based on a nonlinear transmission line (NLTL) structure. Results show the second harmonic is more than 13dB lower at 0-V bias than a conventional single-ended NLTL phase shifter. We fabricated both balanced and conventional NLTL phase shifters with the same coplanar waveguide (CPW) design and diodes, and observed that phase shifting and insertion loss for both structures were quite similar, yet harmonic distortion was greatly improved in the balanced structure.     

Phase shifter with high phase shifts using defected ground structures

A novel phase shifter with defected ground structures (DGSs) for higher phase shift range is presented. The varactor diodes are mounted on DGSs of termination loads to control the large phase variation of the DGS at resonance. The experimental results of the proposed phase shifter show a 60/spl deg/ increase in maximum phase shift compared with that of a conventional one.     

High-Tc superconducting microwave phase shifter

The relation between the surface impedance Z_S(=R_S?jX_S) of superconductors and DC current I has been derived to determine the propagation constant of a superconducting microstrip line, and the relation between the phase delay ? of the superconducting microstrip line and DC current I is also presented. On the basis of these analytical results, a microwave phase shifter has been made by using YBCO superconducting thin film. In this paper, we describe the design principle of phase shifter, its fabrication, and present the experimental results. These measured values agree well with the theoretical curves.     

Magnetically tuned surface-acoustic-wave phase shifter

A novel technique for achieving variable phase shift in surface-acoustic-wave devices is demonstrated. By depositing a thin film of magnetostrictive material onto the surface of a conventional surface-acoustic-wave delay line, the wave velocity can be varied by adjusting an externally applied magnetic field. Experimental results are presented for a nickel film on a lithium-niobate substrate, and several possible applications are mentioned.     

Voltage variable microwave phase shifter

Results are given on the fabrication, test and theory of operation of a voltage-controlled, continuously variable phase shifter designed to operate from DC to 150 GHz. The device was fabricated in a way that makes it compatible with current gallium arsenide monolithic microwave circuit technology.