We present here a new pattern with compact size of Ultra Wideband (UWB) microwave filter. The filter is based on quarter-wave length short-circuited stubs model. We introduced here a new schematic model by extracting all parasitic elements such as T- junction and discontinuity in our new pattern of UWB filter. This new filter has minimal number of vias and improved frequency bandwidth, insertion loss and return loss. It is fabricated on RT Duroid 5880 with 0.508 mm of substrate thickness. The final dimension is measured as 21 mm × 14 mm. It is not only compact, but also delivers excellent scattering parameters with magnitude of insertion loss, |S21| lower than 0.85 dB and return loss better than −11.6 dB. The fractional bandwidth is 109% from 3.06 GHz to 10.43 GHz. In the pass band, the measured group delay varies in between 0.47 ns to 0.32 ns, showing stability with minimum variation of only 0.15 ns.

/pdf/novel-compact-microstrip-ultra-wideband-filter-utilizing-1oyjllg93k.pdf

Novel compact microstrip ultra-wideband filter utilizing short-circuited stubs with less vias

Two 3-5-GHz low-power ultra-wideband (UWB) low-noise amplifiers (LNAs) with out-band rejection function using 0.18- ?m CMOS technology are presented. Due to the Federal Communications Commission's stringent power-emission limitation at the transmitter, the received signal power in the UWB system is smaller than those of the close narrowband interferers such as the IEEE 802.11 a/b/g wireless local area network, and the 1.8-GHz digital cellular service/global system for mobile communications. Therefore, we proposed a wideband input network with out-band rejection capability to suppress the out-band properties for our first UWB LNA. Moreover, a feedback structure and dual-band notch filter with low-power active inductors will further attenuate the out-band interferers without deteriorating the input matching bandwidth in the second UWB LNA. The 55/48/45 dB maximum rejections at 1.8/2.4/5.2 GHz, a power gain of 15 dB, and 3.5-dB minimum noise figure can be measured while consuming a dc power of only 5 mW.

https://ir.nctu.edu.tw:443/bitstream/11536/5869/1/000274390900004.pdf

Analysis and Design of Two Low-Power Ultra-Wideband CMOS Low-Noise Amplifiers With Out-Band Rejection

A new transversal coupling network is proposed to design of multiple-band bandstop fllters. The resonators in the proposed transversal coupling network have a few of center frequencies and some of them have similar or the same resonating frequency to realize multiple-band bandstop suppression, which are applied to reject pulse signals or bandwidth signals in broadband technique applications. A triple-band bandstop fllter is designed by adopting substrate integrated waveguide to demonstrate the feasibility of this proposed network.

/pdf/analysis-and-design-of-multiple-band-bandstop-filters-38s6lgm7s4.pdf

Analysis and Design of Multiple-Band Bandstop Filters

A novel design of planar dual and triple narrow-band bandstop fllter is presented by adopting the proposed meandered slot defected microstrip structure (MS-DMS) and the simplifled spiral microstrip resonator (SSMR). Through this design, the stopbands of the dual- and triple-band bandstop fllters can be individually controlled and the improved spurious responses are achieved. First, the fundamental and the flrst spurious resonances of the MS-DMS and SSMR are analyzed to provide the design rules. Then, by utilizing the prominent stopband of the MS-DMS and the stopband produced by the SSMR coupled to main microstrip line, a dual narrow- band bandstop fllter is constructed before its design procedure is outlined. Based on above investigations, a triple narrow-band bandstop fllter is implemented by inserting extra SSMRs to another side of the main microstrip line of the dual-band fllter to generate a new stopband. To verify the aforementioned design concepts, a dual and triple narrow-band bandstop fllter are designed, simulated and tested. Both the simulation and measurement indicate that the fabricated fllters exhibit good stopband/passband performance and improved flrst spurious resonance. Moreover, these fllters are simple to design and quite compatible with planar fabrication technique, making them very attractive for practical applications.

/pdf/design-of-planar-dual-and-triple-narrow-band-bandstop-3v3u17iuih.pdf

Design of Planar Dual and Triple Narrow-Band Bandstop Filters with Independently Controlled Stopbands and Improved Spurious Response

A novel RFID tag employing open-loop resonators is presented in this paper. The resonators have been synthesized using coupled microstrip transmission line. The complete design consists of open-loop resonators based tag, and cross polarized circular patch antenna for transmitting and receiving purpose. The design of 8-bit data encoded tag and the antennas have been prototyped on Rogers 5880 substrate having dielectric constant of 2.2 and loss tangent of 0.0009 for the frequency band between 3.3 GHz and 5.8 GHz. The measured results show a very good performance in the detection of all the 8 bits.

Chipless RFID tag based on open-loop resonator

A design of multiple-stopband filters is presented for the suppression of interfering signals in UWB applications. Since possible interferers can be located at fixed frequencies or within a defined frequency band, the design of both fixed and tunable narrow stopband filter sections is addressed. For multiple fixed stopband filters, bent resonators, coupled to the main line, are introduced in order to more effectively suppress harmonics. A new tunable tapped stopband section is proposed, which allows the simultaneous control of stopband frequency and bandwidth. The final multiple-stopband design combines fixed and tunable sections and simultaneously suppresses interferences from global system for mobile communication, wireless local area network, worldwide interoperability for microwave access, and industrial-scientific-medical applications. Measurements verify the design process

/pdf/design-of-multiple-stopband-filters-for-interference-44m0zuagmn.pdf

M.Y.-W. Chia

Papers

Design of multiple-stopband filters for interference suppression in UWB applications