A novel frequency discriminated phase controller for high-speedoptical clocks generated from laser diodes

We demonstrate the in-situ frequency discrimination and continuous phase tuning of high-speed optical clocks generated from a directly modulated/encoded laser diode with respect to a free-running microwave clock. This is performed by using a DC-voltage controlled, frequency-discriminated optoelectronic phase shifter (OEPS). The transfer function of the phase shifter versus controlled voltage is linear with a maximum phase-tuning range of up to 1.957π (340°). The tuning responsivity of the OEPS can be adjusted from 50 to 90°/V. The fluctuation and drift in phase of the controlled signal are about 0.05° and 0.003°/min. The tuning resolution of 0.2° at a 3-mV increment of controlling voltage is achieved by using a high-precision voltage regulator. Relative timing jitter of the controlled optical microwave clock is less than 5 ps     

Nonlinear microwave spin wave interferometer

The characteristics of a nonlinear microwave spin wave interferometer were experimentally studied for the first time. The interferometer was implemented according to a bridge scheme with a nonlinear spin wave phase shifter based on an yttrium-iron garnet film. The maximum sensitivity of the nonlinear interferometer with respect to the input signal level was reached with a phase shifter operating on the forward volume spin waves. In the GHz frequency range, an increase in the microwave power up to a few mW led to a signal phase shift exceeding 180 °.     

A novel driver with adjustable frequency and phase for traveling‐wave type ultrasonic motor

Abstract

This paper describes the design of a traveling‐wave ultrasonic motor (TWUSM) drive circuit, intended to simultaneously employ both driving frequency and phase modulation control. The operating principles and a detailed analysis of the proposed driving circuit, consisting of voltage‐controlled oscillator (VCO), voltage‐controlled phase‐shifter circuit and non‐resonant power amplifier converter, are introduced. To drive the USM effectively, a two‐phase power amplifier converter using non‐resonant output was designed to provide a balanced two‐phase voltage source. Two‐phase output driving voltages could be maintained at the same peak voltage value as the driving frequency under varying phase‐modulation processes. Detailed experimental results are provided to demonstrate the effectiveness of the proposed driving circuit.     

Linear frequency tuning of SAW resonators

Frequency tuning in SAW (surface acoustic wave) resonator-stabilized oscillators is normally accomplished via utilization of a voltage-controlled phase shifter. The design of abrupt junction varactor diode-inductor networks which employ impedance transformation techniques to obtain linear frequency tuning of two-port SAW resonators is reported. The approach is similar to that previously developed for linear tuning of bulk wave, quartz crystal resonators. This technique uses varactor diode parallel inductance to provide a linear reactance versus voltage network, which is effectively connected in series with the resonator motional impedance in order to tune the effective resonator center frequency. Typical tuning ranges are significantly larger than those achievable using the phase shifter approach, and are on the order of 400 ppm for the 320-MHz resonator used.     

Design of a vector-sum integrated microwave photonic phase shifter in silicon-on-insulator waveguides

An orthogonal vector-sum integrated microwave photonic phase shifter (IMWPPS), consisting of mode-order converter multiplexers (MOCMs), a variable optical power splitter (VOPS), an optical switch (OS) and fixed time delay lines (FTDLs), was theoretically demonstrated in a silicon-on-insulator wafer. MOCMs, as a key element of our device, were employed to generate orthogonal vector signals and served as lossless optical combiners. Combining with the thermo-optical VOPS, OS and FTDLs, the microwave phase shift of 0～2π could be achieved by a refractive index variation of 0～15×10(-3) in the millimeter wave band. The corresponding tuning resolution was about 1.64°/°C. This work, for the first time to our knowledge, provides an attractive solution to transferring a vector-sum method based bulk MWPPS into a integrated one, which is very important for large-scale optically controlled phase array antenna.     

Microwave nonlinear spin wave directional coupler

A nonlinear spin-wave directional coupler for the microwave range has been designed, constructed, and studied for the first time. Each of the four ports of the device can be used as the input or output for a microwave signal. The role of a control element in the coupler is played by a nonlinear spin wave shifter based on a thin ferromagnetic film. A distinctive feature of the proposed device is that an increase in the input power level leads to the signal switching from one to another output, which is caused by a power-dependent variation in the spin wave phase shift.     

金属波导膜厚测量仪的研制

重点介绍了金属波导膜厚测量仪的制备原理、结构和特点 ,测试表明该装置是一台先进的微波性能检测设备 ,C波段圆极化铁氧体移相器波导膜系的膜厚均匀度不大于 5 %。     

Design and analysis of compact work-recovery phase shifter for pulse tube refrigerator

This paper proposes and describes a compact work-recovery phase shifter of a pulse tube refrigerator. Most pulse tube refrigerators recently developed utilize a long inertance tube and a reservoir for phase control between dynamic pressure and mass flow rate at the cold-end of pulse tube refrigerators. An inertance tube-type phase shifter (long inertance tube and reservoir), however, sometimes creates a problem of compact packaging in cryocooler applications and dissipates the work transferred from a compressor as heat. To overcome this disadvantage, an inertance tube-type phase shifter is replaced with a compact work-recovery phase shifter composed of a mass–spring–damper system and a linear generator in a pulse tube refrigerator. This process is achieved by using analogy of the inertance tube-type phase shifter and the mass–spring–damper system. This paper describes a specific configuration of the designed compact work-recovery phase shifter. Using the simulation code, the performance of the pulse tube refrigerator with the compact work-recovery phase shifter is estimated. As a result, the pulse tube refrigerator with the compact work-recovery phase shifter has the comparable cooling capacity with the pulse tube refrigerator with the inertance tube-type phase shifter. If the recovery work is properly utilized, it can also achieve higher efficiency than that of the pulse tube refrigerator with a typical inertance tube-type phase shifter. In this paper, the parametric study of the mass, the spring and damper coefficients of the compact work-recovery phase shifter has been done and their effects are specifically evaluated.     

Controllable liquid-crystal microwave phase shifter

An electrically controlled phase shifter is described, which is based on a resonant microstrip structure with a nematic liquid crystal substrate. It is shown that the proposed device can operate in the centimeter and millimeter wavelength range.     

5 bit, silicon-based, X-band phase shifter using a hybrid pi/t high-pass/low-pass topology

A hybrid pi/t bit passive topology is presented to enable a significant reduction in the die area for a high-pass/low-pass phase shifter is presented. A hybrid-topology 5 bit digital X-band phase shifter was designed, fabricated and tested using a 200 GHz, 0.13 mum SiGe bipolar complementary metal oxide semiconductor (BiCMOS) technology. Size and performance characteristics are presented as a contrast to an all-pi phase shifter recently presented by Comeau et al. using the same SiGe BiCMOS technology and design goals. With similar bit passive performance to the all-pi design, the hybrid shifter allows for a total shifter die-area reduction of 50.5%. The absolute phase error of the shifter was less than plusmn13 from 8 to 12 GHz, with an average insertion loss of -20 dB.     

All-optical 1 x N switching device by use of the phase modulation of spatial solitons

We proposed a new all-optical switching device by using the phase modulation of spatial solitons. The proposed structure is composed of an asymmetric nonlinear Mach-Zehnder interferometer (NMZI) with different lengths for the two arms, the uniform nonlinear medium, and the nonlinear output waveguides. The asymmetric NMZI functions like a phase shifter. The all-optical switching scheme employs angular deflection of spatial solitons controlled by phase modulation created in the asymmetric NMZI. By properly launching the input power and varying the lengths of the delay branch and the uniform nonlinear medium, it is possible for this device to be generalized to a 1 x N all-optical switching device.     

Simple technique for the measurement of two-dimensional linear retardation distributions of wave plates with a phase-shifting Nomarski prism

What we believe to be a new technique for the measurement of two-dimensional retardation distributions of a wave plate (WP) is presented. Phase-shifting interferometry has been applied for determining the relative retardation distribution using a Nomarski prism (NP) as a phase shifter. Absolute retardation distribution is obtained by accurately determining the position of zero retardation in the interference field using white light interference fringes and adjusting the phase distribution with respect to the zero retardation position. The measured absolute retardation distribution of the NP is subtracted from that obtained for the combination of the WP and NP, to get the desired retardation distributions for the WP. The technique is suitable for the measurement of phase retardation of both single and multiple order WPs, as the actual phase retardation distributions are obtained. Results obtained for WPs are presented.     

Demonstration of an Optical Isolator with a Semiconductor Guiding Layer that was Obtained by Use of a Nonreciprocal Phase Shift

We present the experimental study of an optical isolator with a semiconductor guiding layer that was obtained by use of a nonreciprocal phase shift. The isolator is equipped with an optical interferometer composed of tapered couplers, nonreciprocal phase shifters, and a reciprocal phase shifter. The nonreciprocal phase shifter was constructed by wafer direct bonding between the semiconductor guiding layer and the magneto-optic cladding layer. The isolator, designed for the 1.55-mum wavelength, was fabricated to investigate the characteristics of each component. By applying an external magnetic field to the nonreciprocal phase shifter, we achieved an isolation ratio of approximately 4.9 dB in the interferometric isolator.     

Experimental investigation of pulse tube refrigerator with displacer

This article has done the first experimental research on the pulse tube refrigerator with rod type displacer. The displacer with a rod is both used for a phase shifter to adjust the phase angle between the pressure wave and the mass flow, and used to recover the expansion work from the hot end of the pulse tube. How the charge pressure, the operational frequency and the input power affect the performance of the refrigerator is discussed in this article by experimental research. No-load temperature of 38.9K is reached in the preliminary experiment.     

Suppressing pulsed microwave signals in a nonlinear spin wave interferometer

The suppression of S-band microwave pulses in a nonlinear spin wave interferometer was experimentally studied for the first time. The microwave interferometer employed a nonlinear spin wave phase shifter based on an yttrium iron garnet film. A signal representing a periodic sequence of rectangular pulses with a power of up to 2.5 mW passes through the nonlinear interferometer without distortion, while an increase in the pulse power to 13.8 mW results in virtually complete suppression of the pulsed signal.     

Improving the phase sensitivity of a Mach–Zehnder interferometer via a nonlinear phase shifter

We propose a scheme to improve the phase sensitivity of a Mach–Zehnder interferometer. In this scheme, a Kerr nonlinear phase shifter is used to replace the traditional linear phase shifter. We consider two detection approaches: the direct homodyne detection (DHD) and the indirect homodyne detection (IHD). We find that the Kerr nonlinear phase shifter can improve the phase sensitivity of the interferometer, and the DHD is better than the IHD. In addition, we also find that the phase sensitivity of the Kerr nonlinear interferometer is robust against photon losses.     

Measurement of Reflection Coefficient by Means of Slotted Line and Homodyne Detection System

A new method for measuring the complex reflection coefficient in a measurement system with a slotted line and homodyne detector is presented. The measurement involves the investigation of the change of phase angle of wave voltage along the waveguide terminated with the element under test. The principle of measurement and X-band measurement system consisting of waveguide elements are described. The signal fed to the homodyne detector is subject to the rectangular phase modulation which facilitates the construction of the modulator and increases the accuracy of phase determination. The phase shifter used in the system includes a slotted line. The reduction of the influence of residual reflections on the phase shift determination is described. Even with standard waveguide elements the measuring accuracy of amplitude reflection coefficient is found to be approximately 10-3.     

Raising the precision of phase measurements at ultrahigh frequencies with a mismatched phase shifter

Conclusions The errors due to mismatching in phase-difference measurements consist of those produced by the mismatching of the measurement element and of the phase shifter. In the above case we evaluate the errors due to the mismatching of the phase shifter and suggest that the normal measuring method should be changed in order to reduce the error of a given mismatch by a factor of 5–10.Translated from Izmeritel'naya Tekhnika, No. 3, pp. 30–33, March, 1967.     

一种斯特林制冷机移相器的分析研究

对电磁双驱动分置式斯特林制冷机用的移相器进行了较为深入的研究。分析了运算放大器移相器和变压器移相器的功能和优缺点，证实了变压器移相器十分方便可行，而且具有较高的稳定性。本文的分析研究为电磁双驱动分置式斯特林制冷机的进一步功能性研究提供了便利。     

Interferometric optical isolator employing a nonreciprocal phase shift operated in a unidirectional magnetic field

An interferometric optical isolator that employs a nonreciprocal phase shift was studied. The optical isolator consisted of an interferometer with distinct layer structures. A traveling light wave underwent distinct nonreciprocal phase shifts such that the optical isolator could be operated in a unidirectional magnetic field. The optical isolator, in which the waveguide had a HfO2 cladding layer in one of the arms, was designed at a wavelength of 1.55 microm. The propagation distance of the nonreciprocal phase shifter required for the isolator's operation was less than 1.5 mm. The device's total length was less than 2 mm. An optical isolator with distinct layer structures was fabricated and evaluated. An isolation ratio of approximately 9.9 dB was obtained in the unidirectional magnetic field.