Title :
A Wideband-to-Narrowband Tunable Antenna Using A Reconfigurable Filter
Author :
Pei-Yuan Qin ; Feng Wei ; Guo, Y. Jay
Author_Institution :
Univ. of Technol., Sydney, NSW, Australia
Abstract :
A novel microstrip circular disc monopole antenna with a reconfigurable 10-dB impedance bandwidth is proposed in this communication for cognitive radios (CRs). The antenna is fed by a microstrip line integrated with a bandpass filter based on a three-line coupled resonator (TLCR). The reconfiguration of the filter enables the monopole antenna to operate at either a wideband state or a narrowband state by using a PIN diode. For the narrowband state, two varactor diodes are employed to change the antenna operating frequency from 3.9 to 4.82 GHz continuously, which is different from previous work using PIN diodes to realize a discrete tuning. Similar radiation patterns with low cross-polarization levels are achieved for the two operating states. Measured results on tuning range, radiation patterns, and realized gains are provided, which show good agreement with numerical simulations.
Keywords :
antenna radiation patterns; band-pass filters; cognitive radio; microstrip antennas; microstrip lines; microwave antennas; monopole antennas; p-i-n diodes; resonator filters; varactors; PIN diode; TLCR; bandpass filter; cognitive radios; cross-polarization levels; discrete tuning; frequency 3.9 GHz to 4.82 GHz; microstrip circular disc monopole antenna; microstrip line; narrowband state; radiation patterns; realized gains; reconfigurable 10-dB impedance bandwidth; three-line coupled resonator; tuning range; varactor diodes; wideband state; Antenna measurements; Antenna radiation patterns; Broadband antennas; Narrowband; Varactors; Wideband; Cognitive radio (CR); Reconfigurable antenna; cognitive radio; monopole antenna; reconfigurable antenna; wideband antenna;
Journal_Title :
Antennas and Propagation, IEEE Transactions on
DOI :
10.1109/TAP.2015.2402295
