Search

In this paper, a single-pole, double-throw (SPDT) RF switch is designed for the amorphous flat air-ground ad-hoc network platform, which is used to connect the node, low noise power amplifier and power amplifier. The switch controls the transmission and reception of signals in the node according to the variation of excitation voltage. The simulation results show that the RF switch insertion loss is less than 1.5dB, isolation is more than 40dB and the 0.1 dB compression is 38dBm in the frequency band 2.4GHz to 2.5GHz, which can meet the requirements of the ad-hoc network platform. Networking tests results showed that the topology of ad-hoc networks remains stable within a certain distance and the direction of signal in the node is controlled by the switch.

The Cylindrical Surrounding Double-Gate (CSDG) MOSFET can be used to design nanotechnology-based switches that can select the signals from various antennas from/to transmitting receiving sections. This model has the advantages of reduced noise for the various switching circuit application of nanotechnology and radio-frequency technology compared to Double-Gate (DG) MOSFET. In this research, a noise model of CSDG MOSFET has been designed and analyzed to apply the nanotechnology regime with the focus on various noises.

A single-pole four-throw (SP4T) RF switch with charge-pump-based controller is designed and implemented in a commercial 130-nm silicon-on-insulator (SOI) CMOS process. An improved body self-biasing technique based on diodes is utilized to simplify the controlling circuitry and improve the linearity. A multistack field-effect-transistor (FET) structure with body floating technique is employed to provide good power-handling capability. The proposed design demonstrates a measured input 0.1-dB compression point of 38.5 dBm at 1.9 GHz, an insertion loss of 0.27 dB/0.33 dB and an isolation of 35 dB/27 dB at 900 MHz/1.9 GHz, respectively. The overall chip area is only 0.49 mm2. This RF switch can be used in GSM/WCDMA/LTE front-end modules.

This paper presents the design and analysis of a dual function of a switchable resonator for Radio Frequency (RF) switch. The most common configuration of RF switch is Single Pole Double Throw (SPDT) switch that widely used in the wireless communication system. In order to achieve the dual function between isolation improvement and band-stop filter in SPDT switch, two switchable resonators were used that resonated at 2.3 and 5.2 GHz bands. PIN diodes were used as switching elements in the SPDT switch. The main advantages of the dual function of the switchable resonator are minimum usage of switching elements for isolation and integrated band-stop filter in a single device of SPDT switch. As a result, the design showed almost 40 dB of isolation at 2.3 GHz and 39 dB of the notch response of the band-stop filter at 5.2 GHz.

This paper presents the design, fabrication and characterization of an RF MEMS switch. Low actuation voltage and high isolation of the switch were achieved by exploiting buckling and bending effects induced by well-controlled residual stress. The effects of residual stress on improving the switch performance have been investigated using both analytical and numerical methods. The proposed RF switch has been fabricated by surface micromachining. The minimum actuation voltage of the fabricated switch was measured to be 10.2 V. At a 5 GHz signal frequency, the measured insertion loss and isolation are 0.21 dB and −44 dB, respectively. These results demonstrate that low voltage and high isolation of RF MEMS switches can be achieved with proper utilization of residual stresses.

In order to apply micro/nano technologies and Radio Frequency Micro/nano-Electro-Mechanical System (MEMS/NEMS) technologies in the Radio Frequency (RF) field to manufacture miniature, high isolation, low insertion loss, good linear characteristic and low power consumption microwave switches. Through analysis of electrics and mechanics of the RF switch, a novel MEMS helix induction modulated switch which working on 9GHz~20GHz is presented in this paper. The actuation voltage, insertion loss and isolation of the switch are 12V, 0.89dB@9.5GHz, 31.4dB@9.5GHz respectively. The alternating direction implicit finite-difference time-domain (ADI-FDTD) method for a full three-dimensional (3-D) wave presented is used for modeling and analyzing the micromachine switch for the first time. The numerical method is unconditionally stable. The limitation of the maximum the time-step size of the method does not depend on the CFL condition, but rather on numerical errors. Therefore, the time-step size can be arbitrarily set within numerical errors when this method is used. It is more efficient than the conventional finite element method (FEM) in terms of the central processing unit time if the size of the local minimum cell in the computational domain is much smaller than the other cells and the wavelength. Associated with practical model, Mur's superabsorbing boundary condition was developed. Numerical simulation results are compared with those using the FEM and theoretic computation. It has been demonstrated that, with this technique, space discretization with only a few cells per wavelength gives accurate results, leading to a reduction of CPU computation time and improvement of computation efficiency.

In this paper, a fully wafer-level packaged RF MEMS switch has been demonstrated, which has low operation voltage, using a piezoelectric actuator. The piezoelectric actuator was designed to operate at low actuation voltage for application to advanced mobile handsets. The dc contact type RF switch was packaged using the wafer-level bonding process. The CPW transmission lines and piezoelectric actuators have been fabricated on separate wafers and assembled together by the wafer-level eutectic bonding process. A gold and tin composite was used for eutectic bonding at a low temperature of 300 °C. Via holes interconnecting the electrical contact pads through the wafer were filled completely with electroplated copper. The fully wafer-level packaged RF MEMS switch showed an insertion loss of 0.63 dB and an isolation of 26.4 dB at 5 GHz. The actuation voltage of the switch was 5 V. The resonant frequency of the piezoelectric actuator was 38.4 kHz and the spring constant of the actuator was calculated to be 9.6 N m−1. The size of the packaged SPST (single-pole single-through) switch was 1.2 mm × 1.2 mm including the packaging sealing rim. The effect of the proposed package structure on the RF performance was characterized with a device having CPW through lines and vertical feed lines excluding the RF switches. The measured packaging loss was 0.2 dB and the return loss was 33.6 dB at 5 GHz.

In this paper, we present a compact quadrate-gate single-pole double-through RF switch. We could reduce the size of the multiple-gate high electron mobility transistor (HEMT) switch by reducing the length of the ohmic electrode and the distance between the source and drain electrodes without a severe degradation of switch performance. We developed the dielectric overhang gate process to reduce the distance between the source and drain electrodes of the multiple-gate HEMT switch. LC resonance using a stacked multilayer inductor was employed for the enhancement of isolation without extra area consumption.

A π-type RF capacitive switch using about 45-nm-thick HfO2 dielectric layer was fabricated. High isolation performance was obtained in wide-band range when the switch was down-state. The isolation was better than -40 dB at the frequency range of 4–35 GHz. Particularly, the isolation was better than -50 dB in the frequency range of 8–12 GHz, i.e., X band. HfO2 showed excellent process compatibility with conventional microfabrication procedure. The 45-nm-thick HfO2 film was prepared using sputtering at room temperature so that it was feasible to be integrated into RF switch and other microwave circuits. The results of constant bias stressing showed that the ultra thin HfO2 had excellent reliability. The electric breakdown of HfO2 was observed, which had no apparent negative effects on the reliability of the dielectric. HfO2 dielectrics were attractive in the application of RF micro-electro-mechanical systems (MEMS) switch for new generation of low-loss high-linearity microwave circuits.

Micromachined micro-switches have stimulated the development of the core infrastructure technology for the next generation communication systems because of their superior performance. They are fabricated by similar silicon micromachined processes, but the switch structure and its characteristics depend on each application. Micro electro mechanical systems (MEMS) technology has been applied to micro relays, RF switches, and optical switches; as a result, optical and mechanical performance has been improved.

An enhancement mode p-GaN gate AlGaN/GaN HEMT is proposed and a physics based virtual source charge model with Landauer approach for electron transport has been developed using Verilog-A and simulated using Cadence Spectre, in order to predict device characteristics such as threshold voltage, drain current and gate capacitance. The drain current model incorporates important physical effects such as velocity saturation, short channel effects like DIBL (drain induced barrier lowering), channel length modulation (CLM), and mobility degradation due to self-heating. The predicted I d - V ds , I d - V gs , and C - V characteristics show an excellent agreement with the experimental data for both drain current and capacitance which validate the model. The developed model was then utilized to design and simulate a single-pole single-throw (SPST) RF switch.

We report on the device structure and performance of germanium telluride phase change material based ohmic RF switches. Two main types of the phase change switches using direct and indirect heating methods have been designed, fabricated and measured to analyze and compare the performance of germanium telluride in RF switch applications. Both types of switches are proven to have an insertion loss of less than 0.6 dB and an isolation of more than 13 dB for up to 20 GHz. Good linearity and power handling capability results are also measured. A reconfigurable bandpass filter using the indirectly heated phase change switch has also been developed, and shows promising performance. Efforts have been made to further analyze the issues with switching reliability, and explore possible ways of improving the performance of phase change RF switches.

This paper presents the design of single-pole six-throw (SP6T) RF switch with IBM 0.18 μm SOI CMOS technology, which can be widely used in a wireless communication system with its high performance and low cost. The circuit is designed and simulated by using an idea that the total load is divided into six branches and SOI special structures. The insertion loss is less than 0.6 dB, isolation is more than 30 dB, the input power P0.1dB for 0.1 dB compression point is more than 37.5 dBm, IIP3 is more than 70 dBm, the 2nd and the 3rd harmonic compressions are more than 96 dBc, and the control voltage is (+2.46 V, 0, -2.46 V) in the frequency from 0.1 to 2.7 GHz.

A novel radio frequency (RF) switch device has been successfully fabricated using InGaAs metal–oxide–semiconductor field-effect transistor (MOSFET) technology. The device showed drain saturation currents of 250 mA/mm, a maximum transconductance of 370 mS/mm, a turn-on resistance of 0.72 mωmm2 and a drain current on-off (Ion/Ioff) ratio of 1 × 106. The maximum handling power of on-state of 533 mW/mm and off-state of 3667 mW/mm is obtained. The proposed In0.4Ga0.6 As MOSFET RF switch showed an insertion loss of less than 1.8 dB and an isolation of better than 20 dB in the frequency range from 0.1 to 7.5 GHz. The lowest insertion loss and the highest isolation can reach 0.27 dB and more than 68 dB respectively. This study demonstrates that the InGaAs MOSFET technology has a great potential for RF switch application.

Surface recombination and carrier-frequency-dependent intrinsic parameters of an ion-implanted GaAs optical field effect transistor RF switch have been analysed. The study reveals that the gate-source capacitance increases with gate-source voltage, at first slowly and then sharply under enhancement mode with an increase of modulating frequency. however, surface recombination reduces these effects depending upon the trap centre density. The surface recombination effect becomes significant only when the trap centre density is nearly equal to or greater than 1022 m-2. These variations are small in depletion devices. The drain-source resistance is found to increase with increasing modulating frequency, but it decreases with the reduction of trap centre density at a fixed flux density and drain-source voltage. It is also observed that the RC time constant increases significantly with gate length and reduces with increase of trap centre density at a fixed radiation flux density, modulating frequency and drain-source voltage.

The system of RF control of three-electrode electron gun current is described. It consists of a source of microwave signal, coaxial line, coaxial RF switch and RF antenna lead. The system allows one to get the electron beam in the form of bunches with the frequency of the accelerating section to achieve the capture of particles in the acceleration mode close to 100%. The results of calculation and analysis of the elements of the system are presented. Characteristics of the devices are obtained experimentally. The results of using RF control in three-electrode electron gun at electron linear accelerator are described.

A comprehensive and completely parameterized model is proposed to determine the related electrical and mechanical dynamic system response of a voltage-driven capacitive coupled micromechanical switch. As an advantage over existing parameterized models, the model presented in this paper returns within few seconds all relevant system quantities necessary to design the desired switching cycle. Moreover, a sophisticated and detailed guideline is given on how to engineer a MEMS switch. An analytical approach is used throughout the modelling, providing representative coefficients in a set of two coupled time-dependent differential equations. This paper uses an equivalent mass moving along the axis of acceleration and a momentum absorption coefficient. The model describes all the energies transferred: the energy dissipated in the series resistor that models the signal attenuation of the bias line, the energy dissipated in the squeezed film, the stored energy in the series capacitor that represents a fixed separation in the bias line and stops the dc power in the event of a short circuit between the RF and dc path, the energy stored in the spring mechanism, and the energy absorbed by mechanical interaction at the switch contacts. Further, the model determines the electrical power fed back to the bias line. The calculated switching dynamics are confirmed by the electrical characterization of the developed RF switch. The fabricated RF switch performs well, in good agreement with the modelled data, showing a transition time of 7 µs followed by a sequence of bounces. Moreover, the scattering parameters exhibit an isolation in the off-state of >8 dB and an insertion loss in the on-state of

This paper reports the realization of flexible RF/microwave PIN diodes and switches using transferrable single-crystal Si nanomembranes (SiNM) that are monolithically integrated on low-cost, flexible plastic substrates. High frequency response is obtained through the realization of low parasitic resistance achieved with heavy ion implantation before nanomembrane release and transfer. The flexible lateral SiNM PIN diodes exhibit typical rectifying characteristics with insertion loss and isolation better than 0.9 dB and 19.6 dB, respectively, from DC to 5 GHz, as well as power handling up to 22.5 dBm without gain compression. A single-pole single-throw (SPST) flexible RF switch employing shunt-series PIN diode configuration has achieved insertion loss and isolation better than 0.6 dB and 22.9 dB, respectively, from DC to 5 GHz. Furthermore, the SPST microwave switch shows performance improvement and robustness under mechanical deformation conditions. The study demonstrates the considerable potential of using properly processed transferrable SiNM for microwave passive components. Future investigations on transferrable SiNMs will lead to eventual realization of monolithic microwave integrated systems on low-cost flexible substrates.

A push-pull operation is proposed for low voltage actuation of a microelectromechanical (MEM) switch for RF application. The push-pull operation realized by torsion springs and contact electrode height amplification by leverage, lowers the actuation voltage of the MEM switch by reducing the gap between actuation electrodes. The proposed MEM switch is fabricated by gold surface micromachining. Switching operation up to 4 GHz is demonstrated. The actuation voltage is as low as 5 V. The insertion loss of ∼1 dB and the isolation as high as ∼40 dB at 1 GHz are achieved by the push-pull operation.