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.     

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     

Magnetically tuned klystrons for wide-band frequency modulation applications

This paper describes the application of a ferrite-tunedX-band klystron to produce very wide-band frequency modulation with exceptionally low accompanying power variation. By perturbation techniques, a theoretical analysis of the magnetically tuned klystron is made in terms of the static and dynamic intrinisic properties of the ferrite. The observed operating characteristics show good agreement with the predicted behavior. The design of a practical magnetically tuned X-band klystron for frequency modulation application is discussed in detail. Designs which included a fixed bias field transverse to the tuning field allowed frequency deviation over a 600-Mc bandwidth to be obtained with very good linearity at modulation frequencies below 500 cps. The change in power was less than ± 6 per cent. Another model permitted modulation frequency components up to 50 kc but tuning bandwidth was reduced to 300 Mc.     

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.     

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.     

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     

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.     

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.     

High-performance high-power analog phase shifter

A high average power, high figure of merit, X-band, ferrite loaded waveguide phase shifter has been developed. A zinc-doped magnesium manganese ferrite (4πMs=3000 gauss), in combination with a reduced cross-section rectangular waveguide, was used to achieve a figure of merit of 1000 degrees per decibel, which is better than any previously reported mode-free configuration.     

Controllable nonreciprocal optical phase shifter

A device capable of producing a large nonreciprocal phase shift and made of photorefractive materials is proposed. The dependence of this phase shift on a number of parameters is derived using the theory of Kukhtarev et al. (1979).     

Compact digital phase shifter utilising negative phase velocity

A compact digital phase shifter is presented utilising negative phase velocity in metamaterial technology. The phase shifter was designed and it was measured ranging from 0deg to 360deg with discrete increments of 60deg. The measurement result shows that the average increment of phase shift was X = 59.28deg and its standard deviation was sigma = 6.64deg.     

Integrated-optical single-sideband modulator and phase shifter

A scheme of spatially weighted coupling between two waveguide modes is proposed in which the weights form an electrooptically induced periodic coupling structure that can be moved at variable speeds forward or backward along the guide. The device can operate as an optical phase shifter with unlimited phase range, as a single-sideband amplitude modulator or frequency shifter, or as a polarization transformer.     

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.     

Voltage-controlled optical/RF phase shifter

A new fiber-optic device designed to steer the radiation beam of a phased-array antenna has been demonstrated. A radiofrequency (RF) signal at 125 MHz is generated via photomixing at the output of a single-mode fiber-optic interferometer. The phase of the electrical signal is shifted over several cycles in direct proportion to a voltage applied to an optical controller. The controller consists of a Pockels-type optical phase modulator located in one arm of the heterodyne interferometer. Rapid changes in RF phase are feasible. A miniature low-voltage version of the device, based upon integrated optics, is proposed.     

波导二极管移相器的设计

介绍了波导二极管移相器的设计原理和实现方法。运用矩形波导的传输理论,将加载线型移相单元插入矩形波导内,对波导内的24个加载线型移相单元进行调配组合实现五位地址数码控制移相器。实测结果表明该移相器移相范围大、插入损耗低、输入驻波小、转换时间快、移相精度高及耐高功率性好。     

Single PIN diode X-band phase shifter

A new design of microstrip phase shifter is described which uses only one PIN diode per bit of phase shift. Results are presented for a representative device which show good agreement between experimental and theoretical results at X-band. In particular, the device has been shown to yield a useful 20% bandwidth centred on 10 GHz.     

CMOS wideband auto-tuning phase shifter circuit

A novel auto-tuning phase shifter circuit suitable for integrated circuit implementation is presented. The circuit exhibits simple structure and provides phase shifting over three decades of frequency, 2 kHz-2 MHz, with a minimal phase error, less than 3.5%. Simulation results using 0.5 um CMOS technology and power supply plusmn2 V are included.     

Control circuit for ferrite phase shifter

A circuit is described that uses a digitally controlled variable-pulse-duration generator to determine the phase setting of a 9 GHz ferrite phase shifter to an accuracy of within ±4°. The circuit incorporates temperature compensation, test facilities and phase information stored in a read-only memory.     

The distributed Josephson inductance phase shifter

The authors report on a novel microwave phase shifter featuring rapid electronic adjustment, continuous phase control true time delay operation, high device fault tolerance, and very broadband operation. By coupling a large number of superconducting quantum interference devices (SQUIDs) to a superconducting microstrip transmission line, a variable magnetic medium in which the wave velocity is controlled electronically is created. The authors have measured 60° phase shift at 10 GHz, and wideband operation from 5 to 15 GHz for an 8-cm-long Nb transmission line coupled to 1600 SQUIDs, each containing a single Nb/AlO_x/Nb tunnel junction. The observed phase shift corresponds to a change in wave velocity of about 1 part in 60