Solid-state Phase Shifter Research Articles

Твердотельные СВЧ-фазовращатели. Часть 1

Твердотельные СВЧ-фазовращатели. Часть 1

MAcro-Electro-Mechanical Systems (MÆMS) based concept for microwave beam steering in reflectarray antennas

We present a new approach to perform beam steering in reflecting type apertures such as reflectarray antennas. The proposed technique exploits macro-scale mechanical movements of parts of the structure to achieve two-dimensional microwave beam steering without using any solid-state devices or phase shifters integrated within the aperture of the antenna. The principles of operation of this microwave beam steering technique are demonstrated in an aperture occupied by ground-plane-backed, sub-wavelength capacitive patches with identical dimensions. We demonstrate that by tilting the ground plane underneath the entire patch array layer, a phase shift gradient can be created over the aperture of the reflectarray that determines the direction of the radiated beam. Changing the direction and slope of this phase shift gradient on the aperture allows for performing beam steering in two dimensions using only one control parameter (i.e., tilt vector of the ground plane). A proof-of-concept prototype of the structure operating at X-band is designed, fabricated, and experimentally characterized. Experiments demonstrate that small mechanical movements of the ground plane (in the order of 0.05λ0) can be used to steer the beam direction in the ±10° in two dimensions. It is also demonstrated that this beam scanning range can be greatly enhanced to ±30° by applying this concept to the same structure when its ground plane is segmented.

Miniatured Phase Shifter

Objective: RF MEMS has emerged as a technology with immense potential for wireless communication and defence applications. In this work, a 5 bit RF MEMS switched line phase shifter is presented using cantilever switch achieving low actuation voltage. Methodology: In this work 5 different phase shifters are designed to get 5 bit phase shift at a particular frequency 10 GHz. The phase shifters consist of stubs like structure designed in the ground of CPW and MEMS capacitive series switches. Solid-state phase shifters based on p-i-n diodes or Field-Effect Transistor (FET) switches are used because they provide a good planar solution at a variety of microwave frequency ranges. Micro Electro Mechanical Systems (MEMS) phase shifters are progress today are mainly have established designs because of which the solid-state switch is replaced by a MEMS switch. Findings: By analysing theoretically and practically the results showed that a novel RF MEMS switch was capable of liberating less than 0.1dB insertion loss and more than 19 dB isolation between input and output ports at 20 GHz .This RF MEMS switch shows a 5V actuation voltage. Switching time of RF MEMS switches is measured using a theoretical approach. The switches demonstrated maximum switching time of 0.1μs. By using this switch a 5-bit miniaturized phase shifter is designed i.e. 180° bit, 90°, 45°, 22.25° and 11.5° bits were achieved using the switched line type phase shifters at 10 GHz. A novel switched line type phase shifter loaded with multiple switch pairs was developed and was capable of liberating a multiple phase shift angles within single design

Theory and Design of Solid-state Microwave Phase Shifters

Among the large number of microwave components that are at the heart of many communication, radar and other electronic systems, there is a class of components known as ‘control components’. This class comprises mainly three components - switches, attenuators and phase shifters. In this paper we will review some of the commonly used phase shifter circuits which are realized using solid-state devices. These circuits are planar, and are useful for low-to-medium power levels with very high switching speeds. There is of course another, equally important, category of phase shifters, namely the ferrite-based devices for high-power applications which will not be covered here. Our focus is on two-port planar circuits with one or more electrical control inputs which determine the phase shift from the input to the output port.

Novel low-cost beam-steering techniques

This paper summarizes and compares several techniques for beam steering without the use of conventional ferrite or solid-state phase shifters. Three methods are presented: a microstrip patch antenna array fed by a dielectric image line (DIL) controlled by a reflector plate, a multimicrostrip line fed Vivaldi antenna array controlled by piezoelectric transducers (PETs) and a movable grating film fed by dielectric image line. Both theoretical analyses and experimental measurements have been carried out. The measurement results agree very well with the predictions. These new techniques have many advantages, including low cost, broad bandwidth, low loss, wide scan angle, and simplicity. These low-cost beam-steering techniques should have many applications in microwave and millimeter-wave commercial systems.

Modeling of slow-wave EBG structure for printed-bowtie antenna array

The novel printed antenna array consisting of series-fed bowtie radiators, finite-width conductor-backed coplanar waveguide-to-coplanar stripline (FW-CBCPW-to-CPS) transitions, and slow-wave electromagnetic bandgap (EBG) structure is presented. By controlling the size and the cascaded number of EBG cell, this structure appears as a slow-wave transmission line that can exhibit large phase shift with broad bandwidth for antenna array applications. The equivalent circuit is also established to model the phase shift of EBG cell. Measured results show that the antenna array achieves a 50% frequency bandwidth for 10-dB return-loss criterion and an end-fire radiation pattern with a front-to-back ratio greater than 20 dB. Good agreement among measured, full-wave simulated, and calculated results supports the validity of the phase-shifting model of EBG structure to predict the main beam angle of the antenna array. Compared to the conventional solid-state phase shifters for antenna arrays, the proposed slow-wave EBG structure has the advantages of higher compactness and lower cost and it is easier to integrate in the FW-CBCPW-fed bowtie antenna array with broad-band and end-fire radiation characteristics.

H ∞ Control via Normalized Coprime Factorization Approach for Robust Frequency Stabilization Controller Design of Solid-State Phase Shifter

In this paper, a robust frequency stabilization controller design strategy of solid-state phase shifter using H∞ control via Normalized Coprime Factorization (NCF) approach is presented. The proposed control might be implemented also as a new ancillary service for stabilization of frequency oscillations in a deregulated power system. A phase shifter located in series with a tie line between two areas, is capable of controlling the tie line power dynamically, which should be applicable to the stabilization of system frequency oscillations through the interconnections. According to NCF approach, the selection of weighting function in H∞ control design is simplified. The proposed controller has many practical advantages, hence it is easy to implement in real power system. Simulation studies explicitly confirm both disturbance attenuation performance and robustness of the proposed controller against abrupt load perturbation and system uncertainty.

Application of solid-state phase shifter to stabilization of system frequency in an interconnected power system

Nowadays, the electric power industry is in transition to a deregulated market. Under this circumstance, any power system controls such as load frequency control (LFC) and voltage control will serve as an ancillary service, and the power system configuration will be changed by the proliferation of independent power producers (IPPs). In this paper, a control method using a solid-state phase shifter to provide active control facility of system frequency is proposed. In the LFC, the interconnections among some areas are the inputs of disturbances, and therefore, it is important to suppress the disturbances by the coordination of governor systems. In contrast, tie-line power flow control by phase shifters located between two areas makes it possible to stabilize the system frequency oscillations positively through interconnection, which is also expected to provide a new ancillary service for future power systems. This paper proposes a control design method of phase shifters for stabilization of frequency oscillations based on an elementary two-area system and an elementary three-area loop system, which can be extended to the design in a general multiarea system by applying a system reduction method. The design idea is based on stabilization of an interarea oscillation mode between interconnected areas. Numerical results demonstrate the significant effect of the proposed control on the stabilization of frequency oscillations in interconnected power systems. © 2000 Scripta Technica, Electr Eng Jpn, 132(3): 19–29, 2000

Application of Overlapping Decompositions to Control Design of Solid-State Phase Shifter for LFC

This paper proposes an application of overlapping decompositions to control design of solid-state phase shifter for Load Frequency Control (LFC) in a general multi-area interconnected power system. First, the principal idea of control concept for a phase shifter designed by taking advantage of the overlapping decompositions, is presented. Next, a mathematical model of phase shifter for LFC and a coordinated control of the phase shifter with governor systems is developed, in order to achieve the reduced power system model. Then, the method for overlapping decompositions is applied to the reduced system model so as to decompose it into two decoupled subsystems. Subsequently, the eigenvalue assignment method is used to specify control parameters of the phase shifter for mitigating the overshoot of frequency deviations. The control effect on the LFC is investigated in a three area looped interconnected system.

Experimental study on power system stabilizing control scheme for the SMES with solid-state phase shifter (SuperSMES)

The combination of superconducting magnetic energy storage (SMES) and a high speed phase shifter is considered to be a unified power system controller. The combined system has been named as SuperSMES from the viewpoint of its capability. A new control scheme of the SuperSMES for power system stabilization with a simple control sequence composed of local signals has been proposed. This paper shows the results of a new stabilizing control scheme of the SuperSMES for power system stabilization based on experimental results with a 10 kJ superconducting magnet and a 10 kVA model power transmission system.

Application of SMES coordinated with solid-state phase shifter to load frequency control

This paper proposes a sophisticated application of SMES to load frequency control (LFC) in an interconnected power system. The SMES is coordinated with a solid-state phase shifter to enhance the LFC. The frequency control concept and control design of a SMES coordinated with a phase shifter are presented. Numerical results demonstrate the significant effects of LFC by the proposed control and the economical advantage of MJ capacity of SMES.

Distributed analog phase shifters with low insertion loss

This paper describes the design and fabrication of distributed analog phase-shifter circuits. The phase shifters consist of coplanar-waveguide (CPW) lines that are periodically loaded with varactor diodes. The circuits are fabricated on GaAs using standard monolithic processing techniques. The phase velocity on these varactor diode-loaded CPW lines is a function of applied reverse bias, thus resulting in analog phase-shifting circuits. Optimally designed circuits exhibit 0/spl deg/-360/spl deg/ phase shift at 20 GHz with a maximum insertion loss (IL) of 4.2 dB. To the best of our knowledge, this is the lowest reported IL for a solid-state analog phase shifter operating at 20 GHz.

正規化既約分解法に基づくΗ<sub>∞</sub>制御を用いた高速移相器のロバスト周波数動揺安定化制御系の設計手法

Nowadays, the power industry is in transition to a fully competitive scenario. Under this situation, some power system controls such as frequency control will be served as ancillary services. Then, it is important to consider how the system frequency should be controlled. In this paper, a robust frequency stabilization controller design method of solid-state phase shifter is proposed. The frequency controller of phase shifter located in series with a tie line between two areas, is designed based on the idea of enhancing the damping of inter-area oscillation mode. The method of Overlapping Decompositions for system reduction and the Η∞ control via Normalized Coprime Factorization (NCP) approach are used to achieve the proposed design idea. By NCF approach, the weighting selection in Η∞ control design is simplified. Simulation results confirm the performance and robustness of the proposed control against load disturbance and system uncertainties.

高速移相器を用いた連系線潮流制御による連系系統の周波数動揺安定化制御

高速移相器を用いた連系線潮流制御による連系系統の周波数動揺安定化制御

半導体化高速移相器による可変リアクタンス装置(電圧変動の補償)

半導体化高速移相器による可変リアクタンス装置(電圧変動の補償)

Load Leveling of Motor Power Pulsation by a Solid State Phase Shifter.

In this paper, the load leveling of the power pulsation of an induction motor with a pump load by a phase angle regulator is described. The power flow is controlled by varying the phase angle of the voltage vector. The phase angle control enables us to level the input power to reduce the power pulsation. In this case, the energy required to level the input power is stored in the flywheel effect of the motor and pump system. A novel phase angle regulator, Solid State Phase Shifter (SSPS) is also presented, for which the PWM switch schemes are employed between +30° and -30° phase voltage to yield the voltage within ±30° under continuous and rapid control. We carried out a simulation study and an experiment using a vacuum pump load and the induction motor. They were in good agreement on the reduction rate of the power pulsation, which was reduced from 63% to 10% of the average level.

Power system stabilization by superconducting magnetic energy storage with solid-state phase shifter

In this paper, a new configuration of power system controller with a combination of superconducting magnetic energy storage and phase shifter, is proposed to improve the stability of a long distance bulk power transmission system. A power system stabilizing control scheme is also proposed. A related simulation shows that the proposed controller is effective for enhancement of power system stability independent of the location of the controller in a long distance bulk power transmission system.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

半導体化高速移相器による同期機のフライホイール効果を利用した電力制御とその応用

半導体化高速移相器による同期機のフライホイール効果を利用した電力制御とその応用