Ultra-Wideband Bandpass Filter With Sharp Tuned Notched Band Rejection Based on CRLH Transmission-Line Unit Cell

Abstract

Abstract-The proposed filter satisfies the Federal Communications Commission ultra-wideband (FCC-UWB) specifications and also creates and controls sharp rejection notch-bands within the filter's passband in order to provide interference immunity from unwanted radio signals, such as wireless local area networks (WLAN) and worldwide interoperability for microwave access (WIMAX) that cohabit within the UWB spectrum. This filter is based on CRLH concept consisting of an asymmetric transmission line unit cell with a short circuited inductive stub to realize high performance in an operation band from 3.1 to 10.6 GHz with a very compact size of 16.4 mm × 5.0 mm. The main advantage of the proposed filter is that four notch frequencies are tuned in the UWB frequency band. The notch frequencies of the filter can be changed by increasing the length of the coupling stub which is controlled by using switching matrix equipment (Mini Circuit) instead of PIN diodes. To validate the design theory, a microstrip UWB BPF with four notch bands centered at frequencies 6.18, 5.9, 5.7, and 5.5 GHz is designed and fabricated.

A multilayer low parasitic parameter extraction method for synthesis of composite right‐left handed TL

“…By solving (8), the values of inductors and capacitors can be extracted by SREM. To obtain the value of C p in Figure 5, by doing a simple multiplication and division from (7), the value of capacitor can be calculated as (9).…”

“…The designed algorithm in summarize is designing Z section for the known L R and C L , then obtaining the value of 2C p by using relation (9), in the next step, finding the L L and C R by using relation (12) balanced conditions and at the end obtaining C R from relation (10) and designing the Y section for C R and L L . previous sections are investigated.…”

“…For implementation purposes, two similar Z/2 sections are placed at both sides of Y. Therefore, instead of Z section, a Z/2 section is designed and a symmetric geometry is realized and the value of 2C p is obtained by using relation (9) and simulation results. According of the results, the sum of admittance parameters at 0.5 GHz is 0.00124, hence the amount of the capacitor is 0.394 pF and the value of the capacitor in the Y section according relation (10) is 0.979 pF.…”

“…The tunable nonconventional electromagnetic properties resulted in the synthesis and fabrication of composite right-left handed (CRLH) structures for achieving metamaterials. 1,2 These structures have been rapidly used in science and industry with multi-banding 1,3-7 bandwidth enhancement [8][9][10][11] compaction of microwave and antenna devices. [11][12][13][14][15] A CRLH structure is comprised from a series resonator and a parallel one.…”

A compact ultra wide band bandpass filter with dual band notch designed based on composite right/left‐handed transmission line unit cell

“…Several types of CRLH-based structures are used to create the UWB bandpass filters with band rejection characteristics. [11][12][13] In our current work, the symmetrical CRLH-TL based compact UWB bandpass filter is designed with dual band rejection capabilities. In general, when adding notch characteristics to the UWB filters mostly either the WLAN, Wi-Fi, Bluetooth, and any other regular home appliances that works with the bands that comes into the 3.1-10.6 GHz range are either rejected or allowed to pass in Refs.…”