Optimizing design of triplexer chip with low insert loss and high isolation based on planar lightwave circuit

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 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.

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.

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.

A novel high-power-microwave (HPM) waveguide joint is proposed in this paper. By combining the choke slot with the spherical structure, such a joint has not only good electrical performance but also good maneuverability. On the one hand, the choke slot can maintain low surface field strength and good field continuity at the waveguide junction, enabling its high power handling capacity and low insertion loss. On the other hand, the spherical structure is conducive to achieving angular rotation and radial deflection of the waveguide joint and thus improves its dynamic performance. As shown by the design results of the X-band waveguide joint, when the deflection angle does not exceed 2°, the maximal surface electric field is only about 300kV/cm with 3 GW microwave input and the insertion loss is less than 0.12 dB within a relative bandwidth of 8%. The HPM experiment further demonstrates its high power handling capacity and low insertion loss.

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.

High isolation and low insertion loss is highly regarded for the devices designed for high frequency applications. A compact radio-frequency microelectromechanical systems switch on quartz substrate is presented in this paper. The high isolation is achieved by incorporating two membranes in series and shunt configuration on a single substrate while maintaining the compactness of the switch dimensions. The ohmic and capacitive switch membranes are designed in a cavity over co-planar waveguides on substrate. Spring constant, pull-in voltage, pressure distribution, squeeze film air damping, Q-factor, R, L and C for switch are calculated and analyzed by finite element modeler. Eigenfrequency analysis is also carried out using FEM to analyse the mode shape for first 6 eigenfrequencies. Biasing pads are provided on both ends of the switch for electrostatic actuation. Membranes with low spring constant are designed and optimized to work on same voltage level. Stress on membranes is analyzed and taken care of by the including meanders. This proposed switch is showing excellent isolation of $$75$$75 dB and low insertion loss of $$0.13$$0.13 dB at $$28$$28 GHz with need of actuation voltage of $$22.5$$22.5 V for both membranes in complete switch area of $$0.4$$0.4 mm$$^2$$2. The switch has wide bandwidth of $$30$$30 GHz from K and Ka band with above $$62$$62 dB of isolation.

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.

This paper presents the design and simulation of RF MEMS switch using uniform U-Shaped meanders. High isolation and low insertion loss are the main performance parameters enhanced by considering the inductive sections on the design and developing high capacitance using HfO2 as a dielectric medium. The inductive sections in the design help maintain the device at resonance. The proposed uniform U-shaped meanders lower the spring constant and reduce the Pull-in-voltage of the switch. The performance characteristics are observed by simulating the proposed switch in the electromechanics environment using the COMSOL FEM tool. The switch exhibits a low Pull-in-voltage of 5.2 V with a very low switching time of 23.1 µs. Total capacitance of 42.19 fF is formed during upstate which provides a low insertion loss of less than 0.1 dB. Capacitance of 19.11 pF during downstate provides high isolation of − 42.11 dB.

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.

A waveguide lens, composed of multistage polymer-filled thin grooves in a silica planar lightwave circuit (PLC) is proposed and a low-loss structure has been designed. A waveguide lens in a silica slab waveguide has been fabricated using reactive ion etching (RIE) and formed by filling with polymer. Both an imagding optical system and a Fourier-transform optical system can be configured in a PLC using a waveguide lens. It renders the PLC functional and its design flexible. To obtain a shorter focal length with a low insertion loss, it is more effective to use a multistage lens structure. An imaging optical system and a Fourier-transform optical system with a focal length of less than 1000 µm were fabricated in silica waveguides using a multistage lens structure. The lens imaging waveguides incorporate a 16–24-stage lens, with insertion losses of 4–7 dB. A 4 ×4 optical coupler, using a Fourier-transform optical system, utilizes a 6-stage lens with losses of 2–4 dB.

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.

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.

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.

Optical splitters are essential for the construction of optical networks such as fiber-to-the home systems. These devices should exhibit not only good optical characteristics such as low loss and polarization insensitivity but also long-term reliability. Silica-based planar lightwave circuits (PLCs) on Si can form one of the most suitable Y-branching splitters because they have the advantages of low loss, low coupling loss to optical fibers and high reproducibility[l]. When PLC splitters are used in practice, the input and output fibers must be connected to waveguides. Therefore, it is necessary to establish a precise connection technique and confirm its long-term stability. However, neither the connection performance of splitters with up to 32 ports nor the long-term reliability of fiber-connected splitters have yet been evaluated in detail. Here, we describe the connection performance and reliability of 1×8 and 1×32 splitter modules. We have chosen strict Bellcore requirements [2] as the first step in evaluation of the PLC splitter reliability. The requirements are recognized as a standard for reliability tests on optical devices, and define the optical criteria as well as the test conditions.