A rotatable and flexible high-power-microwave waveguide joint.

In this paper Double Resonator Topology is used to achieve high isolation and low insertion loss in single pole double through (SPDT) switch. This SPDT switch is based on GaAs MESFET and operates in the band of 8 to 11 GHz. This circuit is tuned to give optimum very high isolation and low insertion loss in 9-10 GHz frequency band. It uses one series and three shunt branches. One series and one shunt branch capacitances are resonated out with parallel inductance. This circuit is fabricated and performance measured. The measured performance of this MMIC SPDT switch has insertion loss lower than 2 dB and isolation better than 46 dB in 9-10 GHz and insertion loss lower than 2.2 dB and isolation better than 42 dB in 8-11 GHz. This circuit has to be integrated with other component to demonstrate X-band core chip.

This paper presents the realization of a tunable bandpass filter with high selectivity and low insertion loss using one tunable composite right/left-handed (CRLH) cell. The tunable CRLH cell is proposed with varactor diodes loaded both on series and shut circuits. Two shut circuits are designed to form the needed paralleled CR and LL, by which two transmission zeros beside the passband are obtained at the same time. Each varactor diode is shunted by a lumped capacitor for lower insertion loss. The filter is tuned by only one DC bias, which results in easily control and compact size. The measured results agree well with the simulated results, and a tunable range of the center frequency from 1.75 to 2.25 GHz is achieved in measurement with the insertion loss less than 2.5 dB.

This paper presents the simulation of a triplexer design for improving insertion loss and isolation. Triplexer structure consists of 3 sections of microstrip transmission line and resistor models; the first is input matching impedance section for tri-bands frequency, the second is power combiner section for output power combining, and the third is isolation section for isolation of each port. The three triplexer #1, #2 and #3 are validated for input impedance, return loss, insertion loss and isolation at 0.915, 1.8 and 2.45 GHz of operating frequencies. These simulation results of matched input impedance, low return loss, high insertion loss and high isolation in terms of scattering parameters are shown the characteristic for triplexer #1. The mismatched input impedance, high return loss, high insertion loss and high isolation are shown the characteristic for triplexer #2. However, matched input impedance, low return loss, low insertion loss, and high isolation are shown the good agreement of characteristic for triplexer #3.

In this paper, a compact 1.71-2.69GHz diplexer is designed and fabricated for mobile phone terminals based on high-resistivity silicon (HRS) integrated passive device (IPD) technology. Low insertion loss and compact size can be achieved by utilizing new LC resonances to provide transmission zeros. The chip size of the diplexer is 1.525mm×0.95mm×0.1mm. Test results show that the operating center frequencies of the low and high frequency bands of the diplexer are 1.94 GHz and 2.595 GHz, respectively. The low band maximum insertion loss is 1.3dB in 1.71GHz ~ 2.17GHz. The high band maximum insertion loss is 0.7dB in 2.5GHz ~ 2.69GHz. The isolation between two bands is better than 11.2dB in 1.71GHz ~ 2.69GHz.

We demonstrate a simple and effective strategy for implementing a polarizing beamsplitter for the terahertz spectral region, based on an artificial dielectric medium that is scalable to a range of desired frequencies. The artificial dielectric medium consists of a uniformly spaced stack of metal plates, which is electromagnetically equivalent to a stacked array of parallel-plate waveguides. The operation of the device relies on both the lowest-order, transverse-electric and transverse-magnetic modes of the parallel-plate waveguide. This is in contrast to previous work that relied solely on the transverse-electric mode. The fabricated polarizing beamsplitter exhibits extinction ratios as high as 42 dB along with insertion losses as low as 0.18 dB. Building on the same idea, we also demonstrate an isolator with non-reciprocal transmission, providing high isolation and low insertion loss at a select design frequency. The performance of our isolator far exceeds that of other experimentally demonstrated terahertz isolators, and indeed, even rivals that of commercially available isolators for optical wavelengths. Because these waveguide-based artificial dielectrics are low loss, inexpensive, and easy to fabricate, this approach offers a promising new route for polarization control of free-space terahertz beams.

The design procedure of a novel compact ultra-wideband (UWB) filter with high selectivity and low insertion loss is presented in this paper. The proposed filter consists of a simple planar combline filter at the top of a substrate and a non-intuitive shape of the defected ground structure (DGS) on the other side. The UWB filter is obtained by optimizing the shape of DGS and the combline parameters with a mixed integer genetic algorithm. The mixed integer genetic algorithm optimizes both continuous and binary values simultaneously. The continuous values define the combline parameters while the binary values define the shape of DGS. The detail of the design procedure is presented and validated by fabricating a prototype of the proposed filter. The measured insertion loss of the proposed filter in the mid-band frequency is less than 0.5 dB. The measurement results also show that the proposed UWB filter with a very compact structure has five transmission zeroes at the upper and lower stop bands.

The authors present a straightforward and effective approach for minimizing insertion loss (IL) of varactor-based frequency-agile microstrip passive circuits, where varactors are employed as elements of variable reversal capacitances to attain reconfigurabiltiy/tunability on circuit characteristics. Technically, the proposed approach mimics the required capacitances using the varactors together with the SMD capacitors/inductors rather than entirely using the varactors. With the proposed capacitance synthesis, the varactors are able to operate at a higher quality factor so that IL of the entire circuit is minimized. Also, the capacitance tuning range is further extended. With the proposed loss-reduction avenue, the circuit agility could be enhanced, and its effectiveness is experimentally demonstrated with agility enhancement of a reconfigurable bandpass filter (BPF) and a reconfigurable balun BPF.

SPDT switches which are used in IFF equipment should have low insertion loss, high isolation, low VSWR, low switching time and high power handling capacity. PIN diodes are usually used in SPDT switches. This paper gives guidelines for selecting PIN diode for SPDT switches. Stripline SPDT switches for which diodes are selected following the guideline given in this paper are designed, developed and fabricated. The experimental results obtained are insertion loss: 0 6 dB (max.), isolation 25 dB (min.), VSWR 1–42 (max.) and switching time (forward-bias-to-reverse bias) 200 ns in the frequency range of 102 GHz to 110 GHz. The switches can handle 1 kW peak power in the temperature range of—40°C to +55°C.

In this letter, a novel compact dual-band bandpass filter (BPF) is designed to achieve the characteristic of low insertion loss and high isolation for global position system (GPS)/wireless local area network (WLAN) applications. This BPF is implemented by properly selecting the impedance ratio (R) and physical length ratio (alpha) of the asymmetric stepped-impedance resonator (SIR) with one step discontinuity. The coupling coefficient between the coupled asymmetric SIRs is calculated by using full-wave simulator IE3D. The proposed filter has very good measured characteristics including a low insertion loss of 1.1 dB for both passbands, a high isolation insertion loss of 55 dB between the two passbands and a wide stopband rejection of 38 dB from 2.7 to 5.3 GHz. Good agreement with responses of electromagnetic (EM) simulation and measurement is compared.

The miniaturization of polarization beam splitters (PBSs) is vital for ultradense chip-scale photonic integrated circuits. However, the small PBSs based on complex hybrid plasmonic structures exhibit large fabrication difficulties or high insertion losses. Here, by designing a bending multimode plasmonic waveguide, an ultrabroadband on-chip plasmonic PBS with low insertion losses is numerically and experimentally realized. The multimode plasmonic waveguide, consisting of a metal strip with a V-shaped groove on the metal surface, supports the symmetric and antisymmetric surface plasmon polariton (SPP) waveguide modes in nature. Due to the different field confinements of the two SPP waveguide modes, which result in different bending losses, the two incident SPP waveguide modes of orthogonal polarization states are efficiently split in the bending multimode plasmonic waveguide. The numerical simulations show that the operation bandwidth of the proposed PBS is as large as 430 nm because there is no resonance or interference effect in the splitting process. Compared with the complex hybrid plasmonic structure, the simple bending multimode plasmonic waveguide is much easier to fabricate. In the experiment, a broadband (Δλ≈120 nm) and low-insertion-loss (<3 dB with a minimum insertion loss of 0.7 dB) PBS is demonstrated by using the strongly confined waveguide modes as the incident sources in the bending multimode plasmonic waveguide.

This paper presents a unique model of shunt capacitive Microelectromechanical switch which works at RF frequency (12-18 GHz) with low insertion loss and high isolation. Low actuation voltage, removal of stiction and making a switch to work at Ku band frequency are main goals of this design. The ribs that are used in this model are made very stiff to avoid stiction problem. Hafnium Dioxide (HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) has been used as dielectric material with high dielectric constant (k~25) leading to high isolation. The designed switch is optimized to work at a very low actuation voltage (~11.32 Volt) with high isolation, -20 dB and low insertion loss, -0.095 dB.

Design optimization of a novel integrated triplexer based on planar lightwave circuit (PLC) for fiber-to-the-home applications is described. The two-mode interference coupler and Mach-Zehnder interference are used to construct the filter chip. Simulation results of high isolation and low insertion loss are gotten for proposed design. Technique tolerance is improved for fabricating device.

This paper presents an approach to the design of three-port H-plane waveguide Y-junction circulator with two partial height ferrite posts in the junction region which has the advantages of high isolation and low insertion loss. With 9.375GHz center frequency and 400MHz bandwidth, the X-band waveguide circulator designed with the approach could be used in microwave measurement systems, whose VSWR is less than 1.2, insertion loss is less than 1dB and isolation is more than 20dB, which could be used in medium power systems and high power systems.

In this paper, we present a novel laterally actuated DC-contact three-state RF MEMS switch. Rotary electrostatic comb-drive actuators which can be rotated both clockwise and anti-clockwise are chosen as the drive mechanism of the switch and are integrated inside of the switch, hence the switch has a very compact structure. The proposed switch is designed in such a way that it can be used in antenna switch applications where having high isolation and low insertion loss are of most important operating characteristics. The switch has three operating states of ON, OFF and deep-OFF. Different FEM simulations are carried out in order to optimize RF and mechanical behavior of the switch. The switch has acceptable RF performance in a frequency range from DC up to 40 GHz with near to zero power consumption. The actuation voltage of the switch is 50 V. The switching time from OFF to ON state or deep-OFF state is 79 µs and return time to OFF state is 130 µs. The switch has an insertion loss less than ź0.87 dB up to 40 GHz, and return loss below ź21 dB at the same frequency range. The OFF state and deep-OFF state isolations are ź35 and ź60 dB up to 40 GHz, respectively.

A new microstrip diplexer with very high output isolation and low insertion losses is presented in this letter. With the adoption of the spiral compact microstrip resonant cell (SCMRC) form into the dual behavior resonator (DBR) microstrip fllter design, a bandpass fllter with high rejection in the upper stopband can be achieved. Therefore, very high output isolation for the diplexer can be realized. Furthermore, the proposed diplexer also has a property of low insertion loss in the passband. To validate the design theory, one demonstrator diplexer has been designed and fabricated; the results indicate that the proposed diplexer has good performance of simple structure, better than 65dB output isolation in the stopband, and less than 1.2dB insertion losses in the passband.