Design Of Diplexer Research Articles

Microstrip diplexer design based on two square open loop bandpass filters for RFID applications

AbstractIn this work, a simple and efficient approach to design a microstrip diplexer is proposed. It is based on the combination of two compact Square Open Loop Resonator band pass filters. These filters are designed for Radio Frequency Identification application at 2.45 GHz frequency. Using the Chebychev approximation, the two filters and diplexer are designed, simulated, fabricated, and measured. The results show that the diplexer presents a high selectivity, a good insertion loss and high isolation (>40 dB) with the compact size. The diplexer also shows a good performance when associated with the patch antenna operating at 2.45 GHz.

Review on Technologies used to Design RF Diplexers

In this review paper we present the recent progress in the design of RF diplexers It is known that diplexers play an important role in many modern telecommunication systems In this context several types of diplexers have been proposed in literature This review is particularly interested in working principle and diplexers role in wireless communication systems It also discusses the main features of a diplexer and a general comparison between the various technologies used to design the diplexer circuits

Design and fabrication of a compact microstrip lowpass-bandpass diplexer with high isolation for telecommunication applications

This study aimed to design and fabricate a lowpass-bandpass (LP-BP) diplexer with high isolation for telecommunication applications including wireless communications. The results revealed that the −3 dB cutoff frequency of the lowpass filter (LPF) was equal to 0.82 GHz. The advantages of the LPF section include a very high suppression factor (SF) parameter (about 4.4), very sharp roll-off-rate (ROF or ζ) parameter (687), and a very high figure of merit (FOM) (about 233491). The bandpass filter (BPF) section was designed applying dual-mode resonators with triband. The central frequencies of these tribands were equal to 2.38, 3.93, and 5.65 GHz. In the following, an SMV-1247-079LF SMD varactor diode is used to adjust the proposed LPF. The tuning range for the proposed LPF is 0.3-0.72 GHz. In the proposed diplexer, the isolation between the output ports was higher than 45 dB. The results of measurements were in good agreement with those of the simulation.

SU-8 GPON Diplexer Based On H-Line Lithography by Direct Laser Writer

In this letter, the design, fabrication, and characterization of an SU-8 GPON diplexer based on directional couplers are presented. The polymeric devices on SiO2/Si lower cladding substrate were directly written by introducing H-nu 470 photoinitiator, which provides substantial improvement in mechanical and thermal stability, reliability, and low loss, allowing flexible prototyping through H-line lithography at a 405-nm wavelength. Design of the filters and waveguide processing and fabrication are described, and the experimental results of the designed diplexer are shown.

Design of New Eight-Channel Diplexer for Multiband Wireless Communication System

In this paper, we proposed a new eight-channel diplexer (1.575/2.4/3.5/5.2 and 1.8/2.6/4.2/5.7 GHz) with a simple source-load input/output structure containing four pairs of coupled asymmetric stepped-impedance resonators (SIRs) in a compact circuit size. By tuning the impedance ratio and the length ratio of the asymmetric SIRs, each resonant mode can be easily determined, and the diplexer with close quad-passbands (quad-channels) can be implemented. The new eight-channel diplexer for multiband wireless communication systems including of global positioning system, global system for mobile communications, Wi-Fi, and 5G mid-band.

A Novel Design of an H-shaped Microstrip Diplexer

Abstract In this paper, a new microstrip diplexer using modified H-shaped resonators with a compact size and high isolation is presented. This circuit is designed for the ISM band at 2.4 GHz and GPS at 1.575 GHz. The proposed diplexer is formed by connecting two band-pass filters designed by using the modified H-shaped resonator and tapped microstrip Input/output (I/O) lines. An analytic study of the H-shaped resonator and an equivalent LC model of the proposed H-shaped band-pass filter were introduced. Two cross-slots are etched in the ground plane of the proposed microstrip diplexer in order to enhance its electrical performances and to set the pass bands at low frequencies. The circuit with defected ground structure is able to operate at the GPS L1 and L2 bands. The electrical performances of the diplexer are investigated numerically by using Momentum integrated in ADS from Agilent technologies and verified with another electromagnetic software CST microwave Studio.

Design of a compact narrowband quad-channel diplexer for multi-channel long-range RF communication systems

This paper presents a novel microstrip quad-channel diplexer based on stub loaded U-shape resonators, which are coupled to the step impedance feed lines. The stubs are loaded inside the U-shape cells creating extra channels without increasing the size of diplexer. The proposed diplexer is miniaturized with an overall size of 0.029 źg2. It operates at 1.67, 2.54, 3.45 and 4.57 GHz for GPS, wireless and WiMAX applications. Due to its narrowband channels, it is appropriate for the modern long-range communication systems, which are widely accepted by the industry. The proposed diplexer has high performance in terms of low insertion and return losses and wide stopband. The insertion losses at the resonance frequencies are 0.5, 0.38, 0.53 and 0.58 while the common port return losses are better than ź 20 dB at all channels. In order to verify the simulation results, we fabricated and measured the designed diplexer. A good agreement between both results is obtained.

Asynchronously coupled resonant junctions for diplexers and multiport filtering networks

AbstractThis article proposes the use of asynchronously coupled resonator junctions in the design of diplexers. This is to ease the control and implementation of the external couplings at the common port of an all‐resonator‐based diplexer. A comparison study has been performed between a conventional diplexer and the proposed diplexer. To further explore the possibilities of the proposed junction technique, a four‐port multiport filtering networks was proposed and designed to function as a double diplexer. Good agreements have been achieved between the measurements of the prototype devices and the simulations.

Design of planar diplexers with improved isolation using the tunable transmission zeros of a dual‐mode cavity filter

A substrate integrated waveguide dual-mode single cavity filter with two inclined slots on top metal plane provides two transmission zeros. It is shown that the feed offset as well as the slot offset both can be used to tune the zeros over a wide range of frequencies. Leakage loss from the slot is negligibly small. Two bandpass filters are fabricated to validate the predicted zero variation. Further, tunability of the zeros is utilised to greatly improve the isolation characteristics of two X-band planar diplexers. Measurement results show that the isolation is better than 30 dB even if the channel separation is as close as 5% of the average frequency. The effect of packaging on the filter characteristics is also presented.

Use of Group Delay of Sub-Circuits in Optimization of Wideband Large-Scale Bandpass Filters and Diplexers

A new method is proposed for the design of large-scale wideband resonator-coupled bandpass filters and diplexers. Corrected group delay responses of sub-circuits in combination with space mapping are used to compute the physical dimensions from the coupling matrix model. The coupling matrices are designed using the available theories. The method is based on dividing the structures into many sub-circuits and calculating the group delay responses of the reflection from which the coupling parameters and cavities’ resonant frequencies can be extracted. Using a linear space mapping, the structures are optimized efficiently. Depending on the structure’s complexity, few to no full-wave optimization is needed to tune the structures to the true designated filtering function. Bandpass filters and diplexers with bandwidths up to approximately 22% have been designed successfully using the proposed approach. A novel stacked cascaded quadruplet filter has been developed using this method. The design of wideband all-pole filters and diplexers are addressed in the paper.

A compact diplexer with a split-ring resonator junction

Diplexers are three-port filtering devices with a junction connecting two channel filters; the common port connects to an antenna which serves the two channel filters bearing the second and the third port. In the design of diplexers, the technique used in connecting the two channel filters is of great importance to the designers. This is because it determines the size, the effectiveness of signal splitting and combining as well as the ease in implementation. In this paper, an asynchronously tuned double split-ring resonator (SRR) was used in joining the two channel filters. Without incurring any extra space for the junction, the SRR, being a dual-mode resonator, also functioned as a resonant pole for each channel filter. A diplexer operating at 2 GHz and 3 GHz with 4% fractional bandwidths and 20 dB return loss has been demonstrated. The interactions between the SRR and the channel filters were investigated. Good agreement between the simulated and the measured responses was achieved.

Design of a novel compact microstrip diplexer with low insertion loss

AbstractIn this article, a microstrip diplexer is implemented based on a novel combination of the coupled lines and spiral structures in order to reduce the circuit size as well as insertion losses. This diplexer with an elliptic function frequency response operates at 2.4/2.79 GHz for wireless applications. Several transmission zeros on the both sides of two passbands are realized, which improve the selectivity. A theory method is presented that helps to miniaturization, control the resonance frequency, improve the insertion loss, and external quality factor simultaneously. The proposed diplexer has a compact size of 0.3λg × 0.25λg with low insertion losses of 0.18/0.39 dB at 2.4/2.79 GHz. The isolation between the two channels (S23) is better than 20.5 dB from DC up to 6 GHz. The designed diplexer is fabricated and measured. There is a good agreement between the simulated and measured results.

High-performance and high-reliability SOT-6 packaged diplexer based on advanced IPD fabrication techniques

A diplexer offering the advantages of compact size, high performance, and high reliability is proposed on the basis of advanced integrated passive device (IPD) fabrication techniques. The proposed diplexer is developed by combining a third-order low-pass filter (LPF) and a third-order high-pass filter (HPF), which are designed on the basis of the elliptic function prototype low-pass filter. Primary components, such as inductors and capacitors, are designed and fabricated with high Q-factor and appropriate values, and they are subsequently used to construct a compact diplexer having a chip area of 900μm×1100μm (0.009 λ0×0.011 λ0, where λ0 is the guided wavelength). In addition, a small-outline transistor (SOT-6) packaging method is adopted, and reliability tests (including temperature, humidity, vibration, and pressure) are conducted to guarantee long-term stability and commercial success. The packaged measurement results indicate excellent RF performance with insertion losses of 1.39dB and 0.75dB at operation bands of 0.9GHz and 1.8GHz, respectively. The return loss is lower than 10dB from 0.5GHz to 4.0GHz, while the isolation is higher than 15dB from 0.5GHz to 3.0GHz. Thus, it can be concluded that the proposed SOT-6 packaged diplexer is a promising candidate for GSM/CDMA applications. Synthetic solution of diplexer design, RF performance optimization, fabrication process, packaging, RF response measurement, and reliability test is particularly explained and analyzed in this work.

Design of a microstrip diplexer with a novel structure for WiMAX and wireless applications

In this paper, a novel combination of coupled lines, loops, step impedance and low impedance sections are used to design a compact microstrip diplexer. The designing method is based on obtaining transmission matrices and finding the effective parameters in tuning the resonance frequencies. T-shape tapped lines feed structures are added to three terminals of the proposed diplexer to decrease insertion losses at the both passbands without increasing the overall size. The proposed diplexer with a total size of 573.11mm2 operates at 2.6GHz for IEEE 802.16 and 802.20 WiMAX technology and 6GHz for wireless applications. The insertion losses at the lower and higher resonance frequencies are 0.6dB and 0.9dB, respectively. The proposed structure is simulated, fabricated and measured. The measurement results are in a good agreement with the simulations.

Design and Analysis of EMIT Filter and Diplexer

In this paper, a novel design of an E-plane waveguide filter, called electromagnetically induced transparency (EMIT) filter, is proposed. This EMIT filter is implemented by a rectangular ring (RR) on one side of the substrate and two strip lines resonators (SLRs) on the opposite side, which brings in electrically induced transparency and magnetically induced transparency by the electrical and magnetic couplings between the RR and SLRs, respectively. An equivalent circuit is developed further. Properties of high selectivity, low insertion loss, flat group delay, and small size of only about 0.2 λg are realized by this design method. A sample has been fabricated and tested. The measured central frequency is 33.77 GHz with 3-dB fractional bandwidth of 9.4% and the minimum insertion loss in the passband is 0.5 dB. Using the proposed miniature EMIT filter, a diplexer is further designed with compact sizes and low insertion losses. The measured minimum insertion losses are 0.9 and 0.5 dB in the lower and upper passbands centered at 31.79 and 34.74 GHz with 3-dB relative bandwidths of 7.2% and 8.6%, respectively. Good agreements between the simulated and measured results are obtained both in the EMIT filter and the EMIT diplexer.

Tunable Bandpass Filter Using a Switched Tunable Diplexer Technique

In this paper, a new technique using two p-i-n diodes to switch between two channels of a tunable diplexer with constant return loss is proposed to design a tunable bandpass filter (BPF) with wide frequency tuning range (FTR). The used third-order tunable diplexer with two independently tuned channels consists of one common varactor-tuned lumped-element dual-resonance resonator and two varactor-tuned LC resonators. The ports of its two channels are connected by a single-pole double-throw switch, so that one port of the tunable BPF is constituted. And its common port serves as the other port of the tunable BPF. In the switched tunable diplexer design, its direct current (dc) bias voltages are also appropriately selected to improve the in-band and out-of-band performances of the tunable BPF. As examples, a third-order tunable diplexer with constant return loss of 15 dB is first designed. The measured results show that the 3 dB cutoff frequency of its lower channel can be tuned from 0.5 to 1.02 GHz, while the 3 dB cutoff frequency of its upper channel can be tuned from 1.01 to 1.78 GHz. Then, a tunable BPF is designed, and its 3 dB cutoff frequency covers from 0.485 to 1.82 GHz. The proposed tunable BPF exhibits good return loss, wide FTR, and compact size.

Novel design of microwave diplexers using gap waveguide technology

ABSTRACTNovel design and implementation of microwave Diplexers utilizing groove gap waveguide resonators is presented. A high performance and cost effective Ku‐band Diplexer composed of fourth‐order TX and RX Chebyshev filters is designed, simulated, and fabricated. The simulation and measurement results show good agreement, which validate the design method. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:1133–1136, 2017

Design of a Microstrip Low-Pass-Bandpass Diplexer Using Direct-Feed Coupled-Resonator Filter

Previous systematic low-pass-bandpass diplexer was using coupled-feed line to design its bandpass channel response. However, a coupled-feed line coupled-resonator bandpass filter typically leads to the realization problem in the external quality factor because of the line space limitation between the coupled-feed line and the resonator. Based on our investigation, systematic low-pass-bandpass diplexer design using direct-feed coupled-resonator bandpass filter to relax this problem has never been published in the literature. Therefore, a low-pass-bandpass diplexer using direct-feed coupled-resonator bandpass filter is presented and a systematic matching design is also included in this letter.

Design of quad-channel diplexer adopting channel filters with impedance transformers

Design of quad-channel diplexer adopting channel filters with impedance transformers

Design of a microstrip dual-frequency diplexer using microstrip cells analysis and coupled lines components

In this paper, a microstrip diplexer composed of two similar resonators is designed. The proposed resonator is consisting of four microstrip cells, which are connected to a coupled lines structure. In order to select a suitable geometric structure, first, all cells are assumed as undefined structures where there is a lack of basic information about their geometry and dimensions. Then, an equivalent LC circuit of the coupled lines is introduced and analyzed to estimate the general structure of the resonator respect to a requested resonance frequency. The proposed diplexer is designed to operate at 2.36 and 4 GHz for wireless applications. The insertion losses (S21 and S31) are decreased significantly at the resonance frequencies, so that they are 0.2 and 0.4 dB at 2.36 and 4 GHz, respectively. The designed diplexer is fabricated and measured and the measurement results are in a good agreement with the simulations.