2013 IEEE Symposium on Wireless Technology and Applications (ISWTA)

This paper demonstrates a reconfigurable dual-mode ring resonator matched bandstop filter. The dual-mode ring resonator structure is composed by two degenerate modes or splitting resonant frequencies using a perturbing stub. The reconfigurable dual-mode ring resonator matched bandstop filter is realized by using PIN diodes as switching elements. This reconfigurable filter provides two states of operation; allpass and bandstop response. Frequency of 1 GHz is chosen to demonstrate this operation. The theoretical analysis together with simulation and measurement results are presented in this paper. As a result, this filter can be reconfigured between allpass and bandstop using PIN diodes at 1 GHz.

Reconfigurable dual-mode ring resonator matched bandstop filter

This paper describes the design of a compact printed microstrip G-shaped monopole antenna for wireless local area network (WLAN application). The antenna has G-shaped resonating element which is designed for the two resonance frequencies at 2.4GHz and 5.2GHz respectively, which are the operating bands for WLAN application. The antenna is constructed by a non-conductor backed G-shaped strip with a mircostrip feed line. The dual band performance can be easily achieved by fine- tuning the length of the resonant path. The antenna is designed and simulated by using Computer Simulation Technology (CST) Studio simulation software. The parametric study with five different ground lengths had been done using parametric sweep. The the measurement results will be compared and analyzed with the simulated antenna. Keyword-monopole antenna, wireless LAN, return loss, radiation pattern, antenna gain

/pdf/parametric-study-on-the-compact-g-shaped-monopole-antenna-43t09goccf.pdf

Parametric Study on the Compact G- Shaped Monopole Antenna for 2.4 GHz and 5.2 GHz Application

In this paper, a bandstop to allpass reconflgurable fllter technique is proposed in Single Pole Double Throw (SPDT) switch design. Proof of concept of the bandstop to allpass reconflgurable fllter is presented. It is physically realized using transmission line and radial stub in 3.5GHz band (3.4 to 3.6GHz). The isolation, insertion loss and return loss of the SPDT switches are analyzed and to validate this technique the prototypes are fabricated using FR4 substrate with a thickness of 16mm. A very good agreement is shown between the simulated and measured results. Using this technique, it is able to produce more than 30dB isolation with minimum number of PIN diodes, thus reducing 42.7% of the total circuit size compared with conventional design. Besides, additional 22.9% of isolation bandwidth can be obtained with the use of radial stub compared with transmission line stub. The potential application of this SPDT switch is Time Division Duplex (TDD) switching for WiMAX and LTE communication system in the 3.5GHz band.

https://www.jpier.org/pierc/pierc39/20.13040313.pdf

Bandstop to allpass reconfigurable filter technique in spdt switch design

In this paper, a novel triplexer using the substrate-integrated suspended line technology is proposed. Two matching circuits are designed to connect the three filter channels for the triplexer construction. The used bandpass filters are composed of a low-pass filter and a high-pass filter, and they have advantages of high controllability and low insertion loss. For the proposed triplexer, two adjacent filter channels compose a duplexer. Based on the design consideration, the triplexer can be extended to a multiplexer. The proposed design is further improved by using a patterned suspended substrate for loss reduction. The triplexer achieves good isolations among the three ports and low insertion losses of 1.4/1.3/0.8 dB for the three channels of 0.8, 2.5, and 5.8 GHz, respectively.

A Novel Triplexer Based on SISL Platform

This paper demonstrates a reconfigurable matched bandstop filter. The filter is based on a lossy allpass network. The lossy allpass network demonstrates the concept and design of perfectly matched bandstop response with a perfect matched at all frequencies. The filter is based on the half-wavelength λ over 2 resonator with gap coupling, parallel with an allpass nominally-90°-phase-shift element, which can be optimized to achieve high Q-factor. The reconfigurable matched bandstop filter can be realized by using PIN diodes as a switching element. This filter provides two state of operation under two conditions. The first condition is that the filter will produce allpass response when the PIN diodes are turned ‘ON’. The second condition is that the filter will produce bandstop response when the PIN diodes are turned ‘OFF’. Theoretical analysis together with experimental results is presented in this paper.

Reconfigurable matched bandstop filter

This paper discusses the potential application of switchable matched parallel-coupled stub resonator for isolation improvement of Single Pole Double Throw (SPDT) discrete switch in wireless communication system. In addition, an absorptive SPDT switch also can be obtained by the use of the matched resonator. Frequency spectrum at 2.010–2.025 GHz band for TD-SCDMA is chosen to demonstrate this technique. The discussion of the conceptual and operation of the matched resonator and the SPDT switch are included in this paper. The circuit is simulated for further analysis in simulation software where parameters of microstrip line and FR4 substrate are taken into account. Result in simulation shows 15 dB return loss at absorptive port with 40 dB isolation at resonant frequency and more than 30 dB of isolation between 2.010–2.025 GHz.

The potential application of switchable matched parallel-coupled stub resonator in SPDT discrete switch design

This paper presents dual-band bandpass filter using defected microstrip structure (DMS). The two DMSs was integrated with short circuit stub bandpass filter to produce high attenuation and good selectivity between dual-bandpass. The DMS was designed at 3 GHz with a fractional bandwidth of about 20% and the attenuation is better than 70 dB. The group delay in the passband of dual-band was lower than 1.2 and 1.5 ns respectively. The design was simulated and fabricated on a Roger Duroid RO4350 with a thickness of 0.508 mm and dielectric constant, er of 3.48. This type of filter is useful in any RF/microwave communication systems to enabling pre-selection of more than one band from interferers. While maintaining its excellent performance, the overall physical and cost reduction can also be achieved using this technique.

Dual-Band Bandpass Filter using Defected Microstrip Structure (DMS) for WIMAX Applications

A new prototype of switchable bandstop to bandpass filter was designed and fabricated by using parallel-coupled lossy resonator. The lossy resonator topology was used to partially compensate for the losses. The fundamentals of having two lossy Q resonator structures are that it exhibits a bandpass filter, where the parallel-coupled resonator is disconnected with the λ/4 wavelength. PIN diodes are used to change the filter's response. In the experiments, the filter exhibited a high-Q bandstop response when the PIN diodes were switched ‘ON’ with an operating frequency of 2.4GHz, an attenuation of 75dB and return loss S 11 > 20dB. The lossy bandpass filter was produced when the PIN diodes were switched ‘OFF’. The theoretical analysis together with the fabrication results were presented in this paper.

M. K. Zahari

Papers

Reconfigurable dual-mode ring resonator matched bandstop filter

Reconfigurable matched bandstop filter

The potential application of switchable matched parallel-coupled stub resonator in SPDT discrete switch design

Dual-Band Bandpass Filter using Defected Microstrip Structure (DMS) for WIMAX Applications

Switchable bandstop to bandpass filter using parallel-coupled resonator