Design Of Microstrip Diplexer Research Articles

Compact microstrip diplexer design using new octagonal resonators for 5G and Wi-Fi applications

The present paper sheds light on designing a new and high performance microstrip diplexer. The latter is based on new octagonal meandrous resonators combined with the connected common port, without adding any transmission line junction, in order to get a miniaturized structure. The suggested compact resonator is formed through combining the octagonal meandrous lines and coupled lines, which create a bandpass filter. These filters operate at 3.5 GHz and 5 GHz which make them suitable for 5G and Wi-Fi applications. Accordingly, an approximated equivalent LC model of the presented octagonal meandrous resonator is suggested and analyzed so as to validate the simulation results. On top of that, the suggested diplexer is compact, as it occupies only 0.0768 λ g × 0.024 λ g. Thus, it attained excellent performance in terms of S-Parameters as the transmission coefficients are about -1 dB and the reflection coefficient is about -20 dB at both channels, whereas the isolation is about -25 dB. Hence, the validation of theoretical and simulated results is carried out through measurements of the manufactured prototype.

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.

A novel microstrip diplexer design with tunable bandwidths and switchable channels for 4.5G applications

In this paper, a novel microstrip diplexer with tunable bandwidths and switchable channels is presented by using dual-mode square loop resonators (DMSLRs). Two resonators at different electrical lengths are coupled to input and output ports with lumped capacitors, and the isolation between the output ports is optimized by means of these capacitors. In order to obtain tunable bandwidth in each channel, varactor diodes are located at the orthogonal corners of the proposed resonators. In addition, the proposed resonators have reference patch elements at the lateral arms to provide convenience of varactor diode capacitances, such as perturbation elements. Depending on the capacitances of the varactor diodes, the bandwidths of each channel can be tuned. Furthermore, each channel can be switched off. The designed diplexer has two channels at the center frequencies of 1.8 and 2.6 GHz, which are allocated to 4.5G applications. Three-dB bandwidths can be tuned between 60 and 160 MHz for the first channel and between 150 and 350 MHz for the second channel. Isolation between the output ports is obtained as better than 18 dB in each channel. The designed diplexer was fabricated and measured, and the measured results were consistent with the predicted results.

Design of a Microstrip Diplexer and Triplexer Using Open Loop Resonators

In this paper a novel design of microstrip diplexer and triplexer using open loop resonators is presented. The proposed diplexer if formed by two band-pass filters for the Industrial Scientific Medical (ISM) applications at 5.8 GHz and the WIMAX applications (IEEE 802.16 WiMAX at 3.17 GHz to 4.2 GHz bands). The microstrip triplexer is designed for the Digital Communication System (DCS) at 1.8 GHz, WIMAX at 3.2 GHz and for the C-band at 4.4 GHz. Each device is formed by a set of filters with a matching network by using open loop resonators and a good arrangement of the transmission feed lines. Several parametric studies were achieved to study the influence of some critical parameters on the performances of the proposed circuits. The LC equivalent circuit of the band pass filter is examined and the values of its components are calculated. ADS Agilent and CST-MWS solvers are used to predict the electrical performances of the proposed circuits. The simulated frequency responses of these structures show good results with insertion losses around 2 dB, return losses better than 20 dB for all channels, and an isolation between all bands better than 20 dB. Besides, several transmission zeros are observed near the pass bands which enhance the selectivity and the isolation of the proposed devices.

Microstrip Diplexer Design Using Common T-Shaped Resonator

This study presents a novel microstrip diplexer with a joint T-shaped resonator. The T-shaped resonator has an extremely small frequency ratio using microstrip with practical line width. Additionally, the T-shaped resonator can be used as a frequency selective signal splitter, making it feasible to design a diplexer for a system with two extremely close bands. The diplexer using a joint T-shaped resonator does not require combining circuits and matching networks. A diplexer used in the UMTS-WCDMA system is designed and measured. The proposed diplexer has high isolation and wide stopband in addition to satisfying the passband requirement. A satisfactory agreement between the simulated results and the measured results validate the proposed configuration.

A novel parallel‐coupled line diplexer excited using slot‐line resonators for ultra‐wideband communications

AbstractIn this letter, a novel design of microstrip diplexer used for ultra‐wideband communication has been proposed. The primary structure of the diplexer comprises two different parallel‐coupled line structures with slot‐line resonators (SLRs), which are used for generating the filtering response with high‐channel selectivity. The diplexer is designed to have the lower and higher passband with the operating frequencies at 3.2–4.8 GHz and 6.5–9.8 GHz, respectively. Experimental results also show a good agreement with the simulated results. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1552–1555, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24356

Complementary split ring resonators for microstrip diplexer design

A new topology for the design of microstrip microwave diplexers, based on the use of quasi-lumped resonators, is presented. Specifically, the receiver (Rx) and transmitter (Tx) filters of the diplexer are implemented by etching complementary split ring resonators (CSRRs) in the ground plane as well as series capacitive gaps and shunt inductive strips in the upper metal level. By this means, narrowband microwave diplexers with transmission zeros can be synthesised, which allow for the improvement of Rx/Tx isolation. A prototype device operative in the 2.4-3.0 GHz frequency band is presented. Measured insertion losses are lower than 2 dB while the isolation between Rx/Tx channels is in the vicinity of 40 dB. Diplexer dimensions (29.8/spl times/16.3 mm), which are small on account of the semi-lumped resonators employed, and performance point to the practical application of these structures in communication transceiver front-ends.