Design of wide-band bandpass filter with tunable notch response of wireless communication system

Abstract

This paper presents design of wide-band bandpass filter with tunable notch response of wireless communication system. This project is to design a five order tunable band-pass filter by using optimum distributed high-pass integrated with Defected Micro-strip Structure (DMS). The wideband frequency is used from 3.1 GHz to 10.6 GHz. The insertion loss and return loss of this project is set to better than 0.5 dB and 20 dB respectively. The DMS is implemented and design after the design of the band-pass filter to remove undesired frequency in wireless communication system. The pin diode is added to act as a switch to tuning the notch response. When the pin diode off, the notch response need to produce a sharp response at 6.8 GHz (RFID) and 8 GHz (X-band satellite communication). When the pin diode on, the notch response is tuned to 4 GHz (C-band satellite communication) with a 400 MHz bandwidth characteristic and a sharp response 6.8 GHz (RFID). All the band reject response must be better than 20 dB. This design is simulated by ADS software and using Roger Duroid 4350B with a dielectric constant of 3.48, substrate thickness 0.508 mm and loss tangent 0.0019.