Ka‐band phased patch array antenna integrated with a PET‐controlled phase shifter

In this article, a 4 × 4 linear‐phased patch array antenna, consisting of four 1 × 4 patch subarrays and a true time‐delay multiline phase shifter, is proposed on a thin film liquid crystal polymer substrate at Ka‐band. The patch antenna is designed with a gain of 6 dBi at 35 GHz and a bandwidth of 23% centered at 35 GHz. To enhance the gain and symmetrize the beam patterns of the 4 × 4 array, a 1 × 4 patch subarray in the E‐plane was designed and characterized. The subarray produces an enhanced gain of 11 dBi and a wide beamwidth of ±38° in the H‐plane for beam steering. The proposed phase shifter comprises a 1 × 4 microstrip line power splitter and a piezoelectric transducer‐controlled phase perturber. A large phase variation of up to 370° and a low insertion loss of less than 2 dB were demonstrated for the phase shifter at Ka‐band. The integrated phased array attains a gain of 15.6 dBi, and a continuous true‐time delay beam steering of up to 33 ± 1° from 31 to 39 GHz. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:199–208, 2016.     

Differential phase shifters based on Schiffman type‐C and type‐F networks with wide phase shift range

This study proposes a class of differential phase shifters based on the Schiffman type‐C and type‐F networks with wide phase shift range. After the phase and bandwidth properties of these two distinct networks are numerically analyzed, two unique advantages of wide phase shift range and wide phase shift bandwidth are revealed. Next, the optimal design parameters for different phase shift values up to 405° are presented to allow for a quick design process. To verify the proposed approach, a 180° differential phase shifter is designed, fabricated and measured. Good performance is achieved with an impedance ratio of 1.959 and 3.7° phase deviation over a phase shift bandwidth of 61%.     

Reconfigurable multibeam feed network for 38 GHz application

A feed network based on substrate integrated waveguide for 38 GHz application is proposed in this article. The network consists of a 90° hybrid, a 180° hybrid, a power divider, and a switchable phase shifter. There are two input ports in the reconfigurable multibeam feed network (RMBFN) and a set of symmetrical radiation pattern will be excited by the two input ports. In addition, the other symmetrical patterns will be obtained by adjusting the different states of the switchable phase shifter. The simulated results show that the S₁₁ and S₂₂ are found to be better than ?13 dB over 37‐40 GHz. Meanwhile, the amplitude of the three output ports is about ?6.6 ± 1 dB, and the phase difference is ±60 ± 10° or ±120 ± 10°. When the proposed RMBFN feeds for an antenna array, four different beams with the main beam pointing to the ±22 ± 3° and ±43 ± 3° are obtained.     

A SiGe BiCMOS phase shifter based on quarter‐wave coupled resonators

This work presents the first example of monolithically integrated phase shifter based on a pass‐band filter architecture. The proposed configuration was realized mapping a classical quarter‐wave coupled filter circuit into its lumped element equivalent. Phase control is achieved by controlling the pass‐band through tunable tanks employing varactor diodes. A demonstrator was prototyped in the 24 GHz ISM band using a 0.25μm SiGe BiCMOS technology. Experimental results show 180° of phase range and maximum transmission losses of 8 dB. The main feature of this configuration is that it allows controlling the transmission losses by design and that its size is extremely compact.     

A new design of multi-bit RF MEMS distributed phase shifters for phase error reduction

In this paper, the major source of phase error for multi-bit MEMS distributed phase shifters, the mismatch between adjacent bits, is investigated. A quantitative account of the phase deviation with the effect of mismatch considered is presented by the simulated results as well as theoretically calculated results. A novel multi-bit distributed MEMS phase shifter aimed to eliminate this error source is proposed. The basic concept for the structure is that, by controlling the phase shifter from the unit cell level, performance deterioration resulted from multiple reflection of the signal in the device in the phase state switching process is avoided. To verify the feasibility of the proposed structure, two X-band 5-bit distributed phase shifters are designed and simulated. Compared with the traditional structure, the average phase errors in all phase states of the two are improved by 28.22 and 36.52 % at 10 GHz. The average RMS phase errors in the bandwidth of 1–12-GHz of 56 frequency points are 1.23° and 1.85°. The improvements of the return loss and insertion loss are also exhibited. Furthermore, the aperiodic distributed phase shifter using different unit cells is introduced to demonstrate that the proposed structure can also be used to decrease the number of MEMS switches of multi-bit MEMS distributed phase shifters.     

A novel approach to minimize RMS errors in multifunctional chips

In this contribution, a novel approach, based on single cells permutations, is presented for the minimization of RMS errors in digitally controlled subsystems. The method is described and demonstrated for phase‐shifting functionalities, but it can be easily applied to different subsystems. By using the proposed approach, the designer is able to choose the best cell configuration, fulfilling arbitrary specification goals. An X‐band GaAs multifunctional chip (MFC) for T/R Module applications, composed by a six‐bit phase shifter, six‐bit attenuator, T/R switch, and on‐board serial‐to‐parallel converter has been designed, realized, tested, and presented here as a test vehicle of the methodology. Measured results include a 4.5° maximum RMS phase error, 1.2 dB maximum RMS spurious amplitude error, and better than 13 dB input and output return losses for all phase and amplitude settings over the whole 9.0–10.2 GHz operating bandwidth. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2012.     

A miniature coupled‐line‐based 3‐dB directional coupler using GaAs PHEMT process

A novel complementary‐conducting‐strip (CCS) coupled‐line (CL) design is proposed to achieve compact size by applying two‐dimensional layout and standard gallium‐arsenide (GaAs) thin‐film technology. To obtain high coupling and satisfy the design rules of GaAs process, mixed‐couple mechanism with edge and broadside coupling are also used. A CCS CL‐based Ka‐band 3‐dB directional coupler is fabricated using WIN 0.15‐μm GaAs pseudomorphic high electron mobility transistor technology. Experimental results show that the proposed directional coupler can cover the entire Ka‐band (26–40 GHz) with through and coupling of approximately 3.7 ± 0.25 dB, and isolation of better than 13 dB. In addition, the phase difference between the two output ports is approximately 90° ± 5°. The occupied area of the prototype (without I/O networks) is only 220 × 220 μm². © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:21–26, 2016.     

高速四相时钟电路设计

基于IHP 130 nm SiGe BiCMOS工艺,设计了一个由基于RC网络相移特性的polyphase移相器和差分时钟缓冲器组成的2 GHz四相时钟电路.因单阶polyphase带宽不足而设计了三阶polyphase级联提高带宽.采用HBT(heterojuntion bipolar transistor)差分时钟缓冲取代MOS(metal oxide semiconductor)单端时钟缓冲,实现更高时钟频率的同时,差分结构也能有效抑制流入采样电容的时钟信号馈通.各模块版图设计均采用高度对称结构来消除相位误差.仿真结果表明,差分输入2 GHz正弦波时,可输出4路相位相差90°方波时钟信号,时钟上升时间约15 ps,4路时钟相位误差小于2.2°,应用到4通道采样保持电路后可成功采样和保持8 GHz正弦输入信号.     

Two dimensional coupled oscillators array with rhombus structure and its application in active antenna array

Beam scanning and forming can be achieved by coupled oscillators array without phase shifter. Active antenna array based on coupled oscillators array has the virtue of low cost, high integration, and high efficiency. Traditional two dimensional coupled oscillators array has been arranged on rectangular lattices, and phase difference of adjacent elements is limited to [-90°, 90°]. Therefore, the beam scanning range is limited to [-30°, 30°] from normal for half wavelength element spacing. A new two dimensional coupled oscillators array with rhombus structure is presented. Phase control method and phase error of the array are also provided. Stability of the array is analyzed, and stable condition is given. When this coupled oscillators array with rhombus structure is used in active antenna array, theoretical results show that phase difference of adjacent elements reach the limit of [-180°, 180°] along the horizontal and vertical directions. Therefore, it has wider beam scanning range than that of a rectangular lattice structure.     

MEMS variable‐capacitor phase shifters part II: Reflection‐type phase shifters

A novel design procedure for reflection‐type phase shifters using capacitive devices is developed. Using this approach, a phase shifter for operation at 26.5 GHz is developed using MEMS variable capacitors reported in Part I of this article. A design optimization procedure is discussed. Design of a CPW hybrid at 26.5 GHz (as needed for this phase shifter) is also discussed. Experimental results validate the design procedure and yield a phase shift of 179.30° at 26.5 GHz. © 2003 Wiley Periodicals, Inc. Int J RF and Microwave CAE 13: 415–425, 2003.     

A low cost approach for the fabrication of microwave phase shifter on laminates

This paper presents a simple and low cost fabrication approach using extended printed circuit board processing techniques for an electrostatically actuated phase shifter on a common microwave laminate. This approach uses 15 μm thin copper foils for realizing the bridge structures as well as for a spacer. A polymeric thin film deposited by spin coating and patterned using lithographic process is used as a dielectric layer to improve the reliability of the device. The prototype of the phase shifter for X-band operation is fabricated and tested for electrical and electromechanical performance parameters. The realized devices have a figure of merit of 70°/dB for a maximum applied bias potential of 85 V. Since these phase shifters can be conveniently fabricated directly on microwave substrates used for feed distribution networks of phased arrays, the overall addition in cost, dimensions and processing for including these phase shifters in these arrays is minimal.

     

The low-cost polarization reconfigurable phased array based on high-precision full 360° phase shifter

In this article, to adapt the various polarization of user terminal, a 1 × 4 C-band high-integrated polarization reconfiguration phased array based on phase shifter matrix is presented. The phased array combined with polarization reconfiguration antenna elements exhibits the desired beamforming patterns and achieves beam polarization reconfiguration simultaneously. Based on the technique of the shunted microstrip open-stub and equalizing resistor, a high-precision reflection-type phase shifter with full 360° continuous phase tuning range is designed for this phased array in this article. The prototype of the polarization reconfiguration phased array is designed and fabricated. Measured results show that proposed phased array works at 5.8 GHz and achieves 21.4% (1.2 GHz) impedance bandwidth and 14.3% (800 MHz) 3 dB axial ratio bandwidth. The beam coverage range at 5.8 GHz is more than 64° with 0.2° beam steering resolution.     

Synthesis of frequency‐independent phase shifters using negative group delay active circuit

This article describes a synthesis method dedicated to the design of frequency‐independent phase shifters (PSs). This innovative PS structure consists in a transmission line cascaded with a negative group delay (NGD) active circuit so that the absolute constant group delays generated by both of them are identical but of opposite signs. So, in principle, it exhibits a constant overall phase and a group delay close to zero. Broadband linear positive phase slopes are obtained through use of an NGD active circuit whose characteristics are recalled prior to the extraction of the PS synthesis relations. The design and simulations of a PS of compact size are reported. The experimental results confirm the expected frequency‐independent transmission‐phase value of 145° ± 10° with an insertion gain of 2 ± 2 dB over a 160% relative frequency band. At last, future prospects allowed by the specific properties of this PS are presented. © 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE , 2010.     

一种用于高能离子注入机射频加速的数字移相器设计

设计了一种基于STM32F405RGT6微处理器和AD9959的高能离子注入机射频加速用数字移相器,首先介绍了移相器的系统组成和工作原理及如何实现高能离子注入机多腔射频加速系统中射频电源的相位控制,然后对微处理器、DDS芯片AD9959、时钟分配芯片AD9510等硬件电路原理和控制软件设计作了详细的介绍;实验结果表明该移相器实现了16通道正弦信号输出,输出波形频率和相位值分辨率分别高达0.02Hz和0.05°,可以完成任意两路之间的相位差调节和设置。该移相器结构简单,性能稳定可靠,能够满足高能离子注入机多腔射频加速系统中射频电源的相位控制要求。     

MEMS variable‐capacitor phase shifters part I: Loaded‐line phase shifter

This article describes the design and characterization of a continuously variable loaded‐line phase shifter using micro‐electro‐mechanical system (MEMS) variable capacitors as phase shifting components. The design and characterization of micro‐electro‐mechanical system (MEMS) variable capacitors for operation at 26.5 GHz is described. A lumped‐element model is obtained from measurements and physical consideration. Experimental results show a capacitance‐tuning ratio of 3.7:1. The capacitor's characterization results are used for designing the phase shifter. A phase shift of 40.5° at 26.5 GHz for a loaded‐line type has been measured. There is good agreement between simulated and measured results. A companion article (Part II) describes the application of these variable capacitors to the design of reflection‐type phase shifters. © 2003 Wiley Periodicals, Inc. Int J RF and Microwave CAE 13: 321–337, 2003.     

A novel differential filtering SIW power divider with high selectivity

A novel differential power divider with bandpass filtering response using the substrate integrated waveguide (SIW) technology is presented. An SIW resonant cavity operated in a balanced resonant mode with odd symmetric electric field distribution is utilized to provide both balanced inputs/outputs and expected common‐mode (CM) suppression in a certain band. Meanwhile, by properly constructing the cross‐coupled topology of SIW resonant cavities, the proposed differential power divider achieves a high‐selectivity bandpass filtering response with two transmission zeros on both sides of the passband. The differential power divider is designed and prototyped on a single‐layer printed circuit board (PCB). The measured center frequency is at 10.6 GHz with 490 MHz 3‐dB bandwidth. A good CM suppression can also be achieved within the operating band. The measured in‐band differential‐mode imbalance for magnitude is ±0.3 dB, while for phase is 0°–4°. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:182–188, 2016.     

A low cost approach for the fabrication of microwave phase shifter on laminates

This paper presents a simple and low cost fabrication approach using extended printed circuit board processing techniques for an electrostatically actuated phase shifter on a common microwave laminate. This approach uses 15???m thin copper foils for realizing the bridge structures as well as for a spacer. A polymeric thin film deposited by spin coating and patterned using lithographic process is used as a dielectric layer to improve the reliability of the device. The prototype of the phase shifter for X-band operation is fabricated and tested for electrical and electromechanical performance parameters. The realized devices have a figure of merit of 70°/dB for a maximum applied bias potential of 85?V. Since these phase shifters can be conveniently fabricated directly on microwave substrates used for feed distribution networks of phased arrays, the overall addition in cost, dimensions and processing for including these phase shifters in these arrays is minimal.     

A novel design of RF MEMS dual band phase shifter

In this paper a novel design of RF MEMS dual band phase shifter is presented. The new design is switched-line type phase shifter which has been constructed by distributed MEMS transmission line (DMTL). Since the constant phase of DMTL can be changed, the proposed design has capability for working at two or more frequencies. The performances of the new design are compared with conventional switched-line design that has been constructed by transmission line of coplanar waveguide. The results show the feasibility of the new design and also show the new design reduces the size and loss of the structure compared with conventional switched-line design. The proposed design is unique approach to achieve a dual band phase shifter using MEMS technology which has low loss and weight with high linearity respect to the other technologies. This dual band phase shifter has very small size than the other passive dual band phase shifters.     

Mutual coupling reduction by SIW ZOR elements on broadside high gain CP beam steering array

In this article, a new circularly polarized (CP) beam steering array antenna based on substrate‐integrated‐waveguide (SIW) is proposed for mm‐wave applications. To generate a wider half power beamwidth (HPBW) and reduce mutual coupling effect a radiation element relying on zeroth order resonance (ZOR) technique has been used which has a treatment such as electromagnetic band gap (EBG) structure to have a specific structure. The antenna element can operate in a bandwidth from 33.82 to 36.37 GHz and AR bandwidth from 34.32 to 35.94 GHz. Besides, the propose element has a HPBW wider than 103°, and a maximum gain of antenna is of 9.2 dBic. A 4 × 4 Butler matrix feed network based on SIW feeding technique is then designed. This feed network includes novel techniques in designing cross‐over and broadband phase shifter. The synthesis of proposed Butler matrix and ZOR elements lead to a four‐beam array antenna with circular polarization can cover a beam switching angles range more than 44° with a gain of 17.6 dBic.     

Microstrip stepped‐impedance ring all‐pass filter and wideband 90° phase shifter

A new all‐pass filter (APF) is proposed. The APF is based on a symmetrical ring, consisting of four sections of transmission line, which are identical in electrical length, different in characteristic impedance. Two input/output ports are connected orthogonally to the ring. The APF is analyzed by using the odd‐even model, and the all‐pass condition is then theoretically obtained. Meeting the condition, the circuit is all‐pass in frequency, but nonlinear in transmission phase. The nonlinear transmission phase with frequency may be adjusted by changing the lines' impedances, while remaining the all‐pass property. Then the APF is used to design a wideband 90° differential phase shifter with adjustable bandwidth. Samples are designed, fabricated and measured. Good agreements are achieved among the theoretic, numerical and experimental results. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:191–195, 2014.