A Ferroelectric Microwave Switch

The rapid variation of an admittance shunting a transmission line is a well-known technique for switching microwave power. The application of a switching voltage to a ferroelectric material provides a convenient means for rapidly varying an admittance between significantly different states. A multistub transmission-reflection-type switch actuated by a switching voltage of 1000 volts has been studied. The operation of the switch depends upon the ability of a ferroelectric variable capacitor to change its capacitance upon application of a switching voltage. A change in capacitance represented by a ratio of two to one results in substantial change in the input admittance of the prototype network shunting the transmission line. The prototype network is a shunt stub and is spaced nominally at /spl lambda/ /4 intervals along the transmission line to form a multistub switch. Each shunt stub includes a ferroelectric variable capacitance which employs lead strontium titanate (Pb/sub 0.315/Sr/sub 0.685/TiO/sub 3/) as the ferroelectric material. Both theoretical and experimental curves of isolation and insertion loss vs. frequency are given for two- and three-stub versions of the switch. For switching voltages of the order of 1000 volts, ferroelectric switches with an isolation of 40 dB, an insertion loss less than 1.0 dB, and a bandwidth of 10 percent are feasible.     

Ultrahigh-Speed Diode Switch for 50 GHz Band Utilizing Avalanche Breakdown in Varactor Diodes

Ultrahigh-speed switches for the 50 GHz frequency range utilizing avalanche breakdown in varactor diodes have been developed as transmitter-modulators for millimeter-wave PCM communication systems. By switching the diode between forward conduction and avalanche breakdown, better performance was obtained than with standard switching conditions. A typical switch of transmission type with a silver-bonded Ge varactor, GSB3C for an input power of +17 dBm at 48 GHz, gave an insertion loss of 3.5 dB with a maximum attenuation of 31 dB. Some of the distinctive characteristics of diode switches utilizing avalanche break-down in varactor diodes are discussed.     

低压低能耗应用的InGaAs／AlGaAsPHEMT单片微波SPDT开关

提出了微波频率下ＰＨＥＭＴ在作开关运用时一种简化的等效电路模型，其模型参数可从对实际ＰＨＥＭＴ芯片的在片微波测试方便地确定。对于电路中元件采用不同尺寸组合情形下所进行的开关性能（插入损耗，隔离度，输入及输出反射损耗）的模拟计算表明，与实验结果符合良好。在对串／并联ＰＨＥＭＴ型ＳＰＤＴ开关的ＣＡＤ优化设计基础上进行了ＩｎＧａＡｓ／ＡｌＧａＡｓＰＨＥＭＴ单片ＳＰＤＴ微波开关的实验研制。从研制的ＭＭＩＣ芯片上在片测试得到的结果为：对应新的个人通信频段的应用，在０～２ＧＨＺ范围内，插入损耗＜１．０ｄＢ，隔离度＞５０ｄＢ，输入及输出反射损耗均优于２４ｄＢ。研制的这种高性能单片开关还可在低至－２．０Ｖ的控制电压下工作。     

宽带GaAsFET微波单片集成单刀双掷开关

本文报道了一种采用串、并联ＦＥＴｓ结构的ＧａＡｓＭＭＩＣ单刀双掷开关。芯片尺寸为０．９７＊１．２３ｍｍ．在ＤＣ－１０ＧＨＺ频率范围内，插入损耗小于２．２ｄＢ，隔离度大于３２ｄＢ，反射损耗大于１２ｄＢ，并关时间小于１ｎｓ，在５ＧＨＺ下的功率处理能力大于２０ｄＢｍ。此开关具有极低的直流功率耗散。     

$Ka$-Band Low-Loss and High-Isolation Switch Design in 0.13-$mu{hbox {m}}$ CMOS

This paper presents designs and measurements of Ka-band single-pole single-throw (SPST) and single-pole double-throw (SPDT) 0.13-CMOS switches. Designs based on series and shunt switches on low and high substrate resistance networks are presented. It is found that the shunt switch and the series switch with a high substrate resistance network have a lower insertion loss than a standard designs. The shunt SPST switch shows an insertion loss of 1.0 dB and an isolation of 26 dB at >35 GHz. The series SPDT switch with a high substrate resistance network shows excellent performance with 2.2-dB insertion loss and isolation at 35 GHz, and this is achieved using two parallel resonant networks. The series-shunt SPDT switch using deep n-well nMOS transistors for a high substrate resistance network results in an insertion loss and isolation of 2.6 and 27 dB, respectively, at 35 GHz. For series switches, the input 1-dB compression point (1P₁) can be significantly increased to with the use of a high substrate resistance design. In contrast, of shunt switches is limited by the self-biasing effect to 12 dBm independent of the substrate resistance network. The paper shows that, with good design, several 0.13- CMOS designs can be used for state-of-the-art switches at 26-40 GHz.     

一种X波段GaAs单片单刀双掷开关

采用0.2μmGaAsPHEMT工艺设计了一种X波段单刀双掷开关单片集成电路。在片测试结果为8～11GHz范围内,隔离度>30dB,在中心频率9.5GHz能够达到45dB,插损<1.2dB。芯片结构非常简单紧凑,仅用了两个并联的PHEMT管。     

A DC-contact MEMS shunt switch

This paper presents the design, fabrication, and performance of a metal-to-metal contact micro-electro-mechanical (MEMS) shunt switch. The switch is composed of a fixed-fixed metal beam with two pull-down electrodes and a central DC-contact area. The switch is placed in an in-line configuration in a coplanar waveguide transmission line. This topology results in a compact DC-contact shunt switch and high isolation at 0.1-18 GHz. The isolation at MM-wave frequencies is limited by the inductance to ground and is -20 dB at 18 GHz. The application areas are in wireless communications and high-isolation switching networks for satellite systems     

Monolithically integrated high-power broad-band RF switch based on III-N insulated gate transistors

We report on the high-performance monolithically integrated RF switch based on metal-oxide-semiconductor III-N heterostructure field-effect transistors (MOSHFETs). The radio frequency (RF) switch microwave monolithic integrated circuit (MMIC) consists of three submicron-gate MOSHFETs connected into /spl pi/-type configuration. In the 0-10 GHz frequency range, the insertion loss is less than 1dB and the isolation is better than 20 dB. The switching powers well exceed 20 W per 1mm of the active element width. The high performance parameters of the switch are achieved due to unique properties of III-nitride MOSHFET, which combines a low channel resistance and high breakdown voltage features of AlGaN/GaN HFETs and extremely low gate leakage currents, large gate voltage swing and low gate capacitance specific to insulated gate design. The combination of these parameters makes MOSHFETs excellent candidates for high-power switching. The experimental data obtained from the RF switch are in close agreement with the results of simulations.     

Small‐Sized High‐Power PIN Diode Switch with Defected Ground Structure for Wireless Broadband Internet

This letter presents a small‐sized, high‐power single‐pole double‐throw (SPDT) switch with defected ground structure (DGS) for wireless broadband Internet application. To reduce the circuit size by using a slow‐wave characteristic, the DGS is used for the quarter‐wave (°/4) transmission line of the switch. To secure a high degree of isolation, the switch with DGS is composed of shunt‐connected PIN diodes. It shows an insertion loss of 0.8 dB, an isolation of 50 dB or more, and power capability of at least 50 W at 2.3 GHz. The switch shows very similar performance to the conventional shunt‐type switch, but the circuit size is reduced by about 50% simply with the use of DGS patterns.     

Principles of creation of microwave delay lines based on nanoscale ferroelectric films

A principle of creating a miniature wideband microwave delay line based on ferroelectric films is considered. On the basis of the results of theoretical and experimental studies, it is shown that the use of films in the design of a delay line makes it possible to increase the range of operating frequencies up to 35 GHz, reduce direct loss to 3.0 dB, and set a delay time of 10 to 90 ns at a control voltage of 30 V /μm.     

DC－40GHzMMIC开关

ＤＣ－４０ＧＨｚＭＭＩＣ开关叶禹康，俞土法，伍祥冰（南京电子器件研究所，２１００１６）提要＊用微波单片集成电路（ＭＭＩＣ）技术设计制作了高隔离度、超快速ＤＣ－４０ＧＨｚＭＭＩＣ开关（ＳＰＳＴ）。开关采用串联、并联单元ＭＥＳＦＥＴ兼用的电路结构。芯片尺...     

DC－40GHzMMIC开关

ＤＣ－４０ＧＨｚＭＭＩＣ开关叶禹康，俞土法，伍祥冰（南京电子器件研究所，２１００１６）提要＊用微波单片集成电路（ＭＭＩＣ）技术设计制作了高隔离度、超快速ＤＣ－４０ＧＨｚＭＭＩＣ开关（ＳＰＳＴ）。开关采用串联、并联单元ＭＥＳＦＥＴ兼用的电路结构。芯片尺...     

A 60–110 GHz Transmission-Line Integrated SPDT Switch in 90 nm CMOS Technology

This letter demonstrates a fully integrated transmit/receive single-pole-double-throw switch in standard bulk 90 nm CMOS process. This switch is based on the transmission-line integrated approach that reduces the effect of parasitic capacitance of transistors in the desired band, and this approach can achieve good isolation and return loss with fewer stages of transistors and broad bandwidth. The switch provides an insertion loss of 3–4 dB and a return loss better than 10 dB in 60–110 GHz. The measured isolation is better than 25 dB. The measured 1 dB compression point of input power is 10.5 dBm at 75 GHz. To the best of our knowledge, this is the first CMOS switch operating beyond 100 GHz.      

All-metal high-isolation series and series/shunt MEMS switches

This paper presents a novel all-metal series switch with several different pull-down electrode geometries. The switch results in an up-state capacitance of 5-9 fF and an isolation of -25 to -30 d8 at 10 GHz. The fabrication process is completely compatible with the standard capacitive (or dc-contact) shunt switch, A dc-30 GHz series/shunt switch is also presented with an isolation of -60 dB at 5 GHz and -42 dB at 10 GHz. This is the highest isolation switch available to-date. The performance is limited by radiation in the CPW lines and not by the series/shunt switch characteristics. The application areas are in high-isolation switches for basestations and satellite systems     

High-isolation CPW MEMS shunt switches. 1. Modeling

This paper, the first of two parts, presents an electromagnetic model for membrane microelectromechanical systems (MEMS) shunt switches for microwave/millimeter-wave applications. The up-state capacitance can be accurately modeled using three-dimensional static solvers, and full-wave solvers are used to predict the current distribution and inductance of the switch. The loss in the up-state position is equivalent to the coplanar waveguide line loss and is 0.01-0.02 dB at 10-30 GHz for a 2-μm-thick Au MEMS shunt switch. It is seen that the capacitance, inductance, and series resistance can be accurately extracted from DC-40 GHz S-parameter measurements. It is also shown that dramatic increase in the down-state isolation (20⁺ dB) can be achieved with the choice of the correct LC series resonant frequency of the switch. In part 2 of this paper, the equivalent capacitor-inductor-resistor model is used in the design of tuned high isolation switches at 10 and 30 GHz     

High power DPDT antenna switch MMIC for digital cellular systems

In this paper, we propose two new types of dual-pole double-throw (DPDT) switch GaAs JFET monolithic microwave integrated circuits (MMICs) for digital cellular handsets. These ICs have the excellent characteristics of low insertion loss and high power handling capability, even with a low control voltage by stacking three JFETs with shallow V_p and using a novel bias circuit using p-n junction diodes. One DPDT switch IC has two shunt FET blocks and can achieve high isolation without external parts. An insertion loss less than 0.6 dB and isolation over 25 dB up to 2 GHz were achieved. P_1dB was about 35 dBm even with a control voltage of 0/3 V. Another DPDT switch IC utilizes parallel resonance of external inductors and parasitic capacitance between the drain and the source of the OFF-state FETs. By attaching 15 nH inductors, for example, the IC exhibited an insertion loss as low as 0.4 dB, an isolation of better than 40 dB at 1.5 GHz, a bandwidth of about 400 MHz for 20 dB isolation, and P_1dB of about 34 dBm with the 0/3 V control     

A New Approach of Lateral RF MEMS Switch

This paper presents a novel lateral series microwave switch fabricated on a silicon-on-insulator (SOI) substrate with a finite ground coplanar waveguide (FGCPW) configuration which is laterally actuated by the electrostatic force. The switch is built with a cantilever beam in the direction of the signal line and a fixed electrode is located opposite the cantilever beam. The mechanical structures are fabricated using SOI deep reactive ion etching (DRIE) and shadow mask technology. The fabricated lateral RF MEMS switch has an isolation of 16 dB at 20 GHz. The insertion loss of the switch is 1 dB and return loss is 15 dB at 20 GHz. The threshold voltage is 19.2 V and switching time is 30 s.     

Characterization of a ferroelectric liquid crystal-based time delayunit for phased array antenna applications

An experimental demonstration of a photonic time delay unit (PTDU) based on ferroelectric liquid crystal devices and Thompson polarization beamsplitters (TBSs) is presented. High signal-to-noise ratios (SNRs) (>96 dB) and optical polarization extinction ratios (ER,~40 dB) are demonstrated for the PTDU using an active noise filter technique. Using a 5 V peak square wave switch drive signal, a 70 μs switching speed is demonstrated for this PTDU that can be used in fast (e.g., 5000 beam/s) beam scanning phased array systems. A shorter switching speed of 35 μs is also observed using a high 15 V peak transitional voltage driving signal     

High-isolation CPW MEMS shunt switches. 2. Design

For pt.1 see ibid., vol.48, no.6, p.1045-1052 (2000). In this paper, the second of two parts, the equivalent RLC model of the shunt switch is used in the design of tuned two- and four-bridge “cross” switches from 10 to 40 GHz. The cross switch attained an insertion loss of less than 0.3-0.6 dB, a return loss below -20 dB from 22 to 38 GHz in the up state, and a down-state isolation of 45-50 dB with only 1.5 pF of down-state capacitance (C_d). Also, an X-band microelectromechanical system (MEMS) switch with an insertion loss of less than 0.2 dB and an isolation of 35 dB is presented. This is done by inductively tuning the LC series resonance of the shunt switch. The MEMS bridge height is 1.5-2.5 μm, resulting in a pull-down voltage of 15-25 V. Application areas are in low-loss high-isolation communication and radar     

Novel high-isolation FET switches

This paper describes novel high-isolation monolithic microwave/millimeter-wave integrated circuit (MMIC) field-effect transistor (FET) switches that have higher isolation characteristics than conventional switches without much insertion loss degradation. The newly developed switches consist of series/shunt FETs and T-shaped R-C-R circuit. Each FET switch utilizes the parasitic capacitive component of the FETs in the off-state to produce a band-rejection filter at the operating frequency. The design method of the newly proposed switches and their characteristics are described herein. With this method, the isolation characteristics are improved by more than 15 dB between 5.4 GHz and 6.4 GHz and more than 20 dB between 5.5 GHz and 6.1 GHz over conventional values