Single-pole Double-throw Research Articles

Metamorphic pin diodes for high isolating and low power consuming millimetre-wave switching MMICs

Two broadband millimetre-wave switching circuits using In0.52Ga0.48As pin diodes grown on a GaAs substrate are presented. To the best of the authors' knowledge, this is the first time that metamorphic pin diodes have been used for switching MMICs. The performances of the pin diodes are discussed and excellent RF results from a single pole single throw (SPST) and single pole double throw (SPDT) switch are demonstrated.

V-band switch configuration based on successive resonance's single pole double throw

V-band switch configuration based on successive resonance's single pole double throw

V‐band switch configuration based on successive resonance's single pole double throw

V‐band switch configuration based on successive resonance's single pole double throw

A bi-directional quasi-optical lens amplifier

A 24-element bi-directional quasi-optical lens amplifier array is presented. The lens amplifier array is designed for X-band, and operates in transmission mode. Single-pole double-throw (SPDT) switches are used to switch between transmit and receive amplifiers. The lens amplifier array demonstrates gains of 5.5 dB at 10.1 GHz in receive mode, and 2 dB at 10.2 GHz in transmit mode, with more than 15-dB ON/OFF isolation. Several applications for the lens amplifier array are demonstrated: a quasi-optical transceiver front-end, reduction of multipath fading, and a multiuser frequency reuse application.

A high‐pass/lowpass phase shifter with resistive matching networks

AbstractThis paper proposes a high‐pass/lowpass phase shifter with improved reflection and phase‐shift characteristics using resistive matching networks. The circuit configuration, reflection characteristics, phase‐shift error‐reduction methods, and the design results are described. The relationship between the reflection of the single‐pole, double‐throw (SPDT) switch and the phase‐shift error is discussed in the high‐pass/lowpass phase shifter using filters to switch the SPDT switch. The reflection of the SPDT switch caused by the parasitic resistance of the switching device is investigated, and an impedance matching method using the resistive matching networks is proposed to reduce reflection. The calculation results for an S‐band phase shifter with the resistive matching networks show that the matching can be achieved even for switching devices with resistance and that the phase‐shift error can be reduced. An S‐band, 90° single‐bit phase shifter has been designed and a low return loss of better than 19 dB and a phase‐shift error of less than 4° are achieved, which confirms the usefulness of the resistive matching networks.

Monolithic 2-18 GHz low loss, on-chip biased PIN diode switches

Two state-of-the-art monolithic GaAs PIN diode switches have been designed, fabricated and tested. These single-pole double-throw (SPDT) switches exhibit insertion losses of 1.15/spl plusmn/0.15 dB over a 2-18 GHz band, which is an unprecedented performance in loss and flatness for monolithic wideband switches incorporating on-chip bias networks. Isolation and return loss are greater than 43 dB and 12 dB, respectively, and the input port power handling is 23 dBm at 1-dB insertion loss compression. These performance characteristics were measured at a nominal bias setting of -8 V, which corresponds to 3.7 mA of series diode bias current and a total dc power consumption of 55 mW. The input power at the third-order interception is 40 dBm. The switches can handle up to 31 dBm (1.25 W) at a higher bias of -18 V and 9.3 mA.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A GaAs high power RF single-pole dual throw switch IC for digital-mobile communication system

Much effort has been devoted to integrate the receiving/transmitting switch since time divided multiple access (TDMA) became widely used for digital mobile communication systems. Conventional Si pin-diode switches require increased current bias as the transmit power is increased to maintain the ON state. A recently-developed GaAs monolithic switch IC can be operated with nearly zero power dissipation. However, there is distortion of the waveform as the transmit power is increased. This limits the power handling capability. Another disadvantage of the GaAs switch IC is that negative voltages are needed to control the ON and OFF states. The high-power GaAs monolithic RF switch IC reported here handles over 5W (PldB: 37dBm) with insertion loss less than 1.0 dB using a circuit to feed forward the signal to the control gate. Positive voltage switching is achieved by integrating large coupling capacitors using high dielectric material, barium strontium titanate (BST), at inputs and outputs. The RF single-pole double-throw (SPDT) switch IC is mounted in an SSO10 package, where better than 25 dB isolation is achieved at a frequency of 1 GHz. >

Low power consumption InAlAs-InGaAs-InP HBT SPDT PIN diode X-band switch

Results for the first monolithic single-pole, double-throw (SPDT) X-band PIN diode switch fabricated with InAlAs-InGaAs HBTs lattice matched to InP are reported. The switch achieves performance similar to that of a GaAs implementation but with half the power consumption. The insertion loss is 0.89 dB and the off-isolation is >35 dB at 10 GHz. The IP3 is 29.6 dBm and the total power consumption is 10.2 mW. Monolithic integration of PIN diodes with an InP-based HBT process provides monolithic switch functions for use in microwave and millimeter-wave communication systems.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Multifunction small-signal chip set for transmit/receive modules

Design and test results for small-signal multifunction MMICs (monolithic microwave integrated circuits) for C-band transmit/receive (T/R) modules are presented. This chip set includes the entire receive path and a portion of the transmit path (seven stages of amplification and 11 passive circuits) in just four chips. These ICs, fabricated with the multifunction self-aligned gate (MSAG) process, demonstrate a high level of integration, excellent performance, and a good yield. The variable-gain low-noise amplifier has 30+or-1 dB gain and 2.5 dB noise figure, the phase shifter SPDT (single-pole double-throw) switch has 8+or-1 dB loss, the T/R buffer amplifier has 6.5+or-0.2 gain and 3.5 dB noise figure, and the variable gain buffer amplifier has 8.5+or-0.5 dB gain and 2.5 dB noise figure. >

Monolithic GaAs p-i-n diode switch circuits for high-power millimeter-wave applications

Two different Ka-band single-pole, double-throw (SPDT) switch circuits using monolithic GaAs epitaxial p-i-n diode technology are presented. The lowest insertion loss is 0.7 dB at 35 GHz, and isolation is better than 32 dB from 30 to 40 GHz. The power-handling capability is at least +38 dBm pulsed and +35 dBm continuous wave. Switching speed rise- and fall times are 2 ns.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A simple technique for failure analysis of MOS IC using liquid crystal : Takahisa Yamaha and Sotaro Nakano. Proc. 15th Symp. Reliab. Maintainab. (Union of Japanese Scientists and Engineers, Tokyo), 57 (1985)

In this paper, high-linearity CMOS single-pole-double-throw (SPDT) RF switches using the proposed field-plate (FP) transistors were fabricated and compared. The 0.13-μm CMOS processed FP metal was connected to the gate terminal and source terminal individually. The discussion throughout dc characteristic, linearity, and power property was given. The gate-terminated FP (FP-G) NMOS provided a lower gate resistance being confirmed for low-noise and high-efficiency design while the source-terminated FP (FP-S) NMOS with relatively lower leakage current, higher linearity, and higher breakdown under high Vds is confirmed to be suitable for high-linearity power design. Several switches using standard transistor, FP-S, and FP-G NMOS transistors were implemented and analyzed. Comparison on the switch characteristics and application has been done. The novel designs indicated that the proposed FP-based switches provided good potentials in power handling and harmonics rejection without sacrifice of power consumption, chip area, and insertion loss.

GaAs MMIC broadband SPDT PIN switch

The first GaAs MMIC using PIN diodes as the active elements is described. The single-pole double-throw (SPDT) switch covers the frequency range 2 to 18 GHz, and can handle incident powers of 1W at X-band. Isolation and insertion loss vary respectively from — 55 dB and 1 dB at 2 GHz to —17 dB and 2.2 dB at 18 GHz.

Improved changeover time between regular and GC–IR on the Digilab FTS-15B

The time needed to change from regular to GC–IR (gas chromatography–infrared spectroscopy) operation on the Digilab FTS-15B Fourier transform infrared spectrometer has been reduced by 40–45 min. First, a single-pole double throw switch connected to the detector selection circuitry on the signal board was mounted in the sample compartment. Second, a 1-in.-diam hole was cut into the top of the purge cover above the position of an operational amplifier that is used to adjust the peak height of the interferogram center burst. These modifications increase the ease and convenience of setting up and removing the GC–IR hardware, allow better utilization of an ’’older’’ model optical bench which requires placement of the GC–IR light pipe in the sample chamber, and provide a time savings.

A thick-film digital potentiometer

This paper describes a digital potentiometer constructed using thick-film techniques and consisting of a. 16-bit TTL shift register and 16 single pole—double throw FET switches connecting an inverted R-2R resistor network to an operational amplifier. The register and switches are formed from unencapsulated ‘ chips ’ mounted on a 2 in. x 1 in. ceramic substrate. The R-2R'network is formed with thin-film and discrete resistors. Constructional details are given that illustrate the practicality of using a thick-film technique for composite analogue/digital circuitry.

A 90-dB Microstrip Switch on a Plastic Substrate (Correspondence)

A single-pole double-throw (SPDT) microstrip switch has been designed on a plastic (polyolefin) substrate to switch two 10-W CW carriers into a common load over the frequency range 1.7 to 2.3 GHz. No tuning adjustments are used over this 30-percent bandwidth to obtain a 90-dB minimum isolation, a 23-dB minimum return loss, and a 1-dB maximum insertion loss. Units now in production typically have a 0.6-dB insertion loss, a 26-dB return loss, and isolation levels of 105/spl plus mn/5 dB.

Octave Bandwidth Adjustable SPDT Power Switch Using p-i-n Diode-Terminated Stubs (Correspondence)

A new two-diode single-pole double-throw (SPDT) power-switch with the operating frequency adjustable within one octave is presented. An experimental model of the switch showed frequency adjustments in narrow bandwidth operation between 0.65 and 1.3 GHz. Frequency adjustment is made by appropriately short-circuiting a transmission line. Using thin-film microstrip lines, the switch was buitt on a 50-mil-thick 1-in by 1-in A1/sub 2/O/sub 3/ ceramic substrate. Switching speed is 100 to 300 ns; power handling capability is 1.5-kW peak power at 1-percent duty factor.

Air conditioning for motor buses : Heating, Piping and Air Conditioning, Vol. 7, No. II

We firstly show the prototype of an ohmic contact Single-Pole Double-Throw Radio Frequency Micro-Electro-Mechanical Systems (SPDT RF MEMS) switch operating at 50–100 GHz. The fabricated ohmic contact SPDT RF MEMS silicon switch moves both laterally and vertically, to improve the isolation at high frequencies by initially misaligning the contact part of the switch over a Coplanar Waveguide (CPW) transmission line. The lateral and vertical movement of the switch is operated by using comb and parallel plate actuators, respectively. The proposed switch was fabricated using Silicon-On-Glass (SiOG) bonding process. The insertion loss of the fabricated switch is measured according to the different operation states of the switch, in the range from 50 to 100 GHz. The fabricated length of the transmission line is 4.6 mm and the measured insertion loss and isolation are 9.13 dB and 24.37 dB at 70 GHz, respectively.