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 共查询到20条相似文献,搜索用时 9 毫秒
1.
Microbend fiber-optic phase shifter   总被引:1,自引:0,他引:1  
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.  相似文献   

2.
Chao  G. 《Electronics letters》1973,9(3):49-51
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.  相似文献   

3.
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  相似文献   

4.
The relation between the surface impedance ZS(=RS?jXS) 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.  相似文献   

5.
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.  相似文献   

6.
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.  相似文献   

7.
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.  相似文献   

8.
9.
Solymar  L. Wilson  T. 《Electronics letters》1985,21(6):234-235
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).  相似文献   

10.
Choi  J.H. Jung  C.W. 《Electronics letters》2008,44(16):975-977
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.  相似文献   

11.
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.  相似文献   

12.
Gates  J.L. White  R.M. 《Electronics letters》1974,10(11):231-232
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.  相似文献   

13.
Voltage-controlled optical/RF phase shifter   总被引:1,自引:0,他引:1  
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.  相似文献   

14.
何明  程海荣 《雷达与对抗》2009,(3):47-49,56
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。  相似文献   

15.
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.  相似文献   

16.
作为太赫兹(THz)相控阵的关键组件,实现实用的THz移相器是亟待解决的热点难题。本文以太赫兹移相器的实现手段为中心,着重介绍了依靠材料特性的液晶移相器和石墨烯移相器以及借助先进工艺技术的微机电系统(MEMS)移相器和InP基底移相器,并从应用角度分析比较了不同实现方法的优势和存在的问题。另外,本文还对MEMS技术实现较低频段太赫兹移相器的可行性和发展前景进行了剖析,阐明其制约因素和技术难点。  相似文献   

17.
A novel configuration for monolithic phase shifters is presented. The layout and fabrication of a single chip, four-bitX-band phase shifter, measuring 3.7 × 2.3 mm, is described in some detail. The first samples to be assessed exhibited full 360 ° coverage at the design frequency, operation throughout X-band, good matches, and an insertion loss less than 5 dB.  相似文献   

18.
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.  相似文献   

19.
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.  相似文献   

20.
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/AlOx/Nb tunnel junction. The observed phase shift corresponds to a change in wave velocity of about 1 part in 60  相似文献   

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