Abstract
AbstractA tunable bandpass filter with switchable single‐/dual‐band responses is presented. The single‐band to dual‐band transformation is achieved by controlling frequencies of poles in a passband. The frequencies of poles are adjusting by using a coupled structure with two coupling capacitors. A filter with both 4‐pole single‐band and 2‐pole dual‐band characteristics is built on a Duroid substrate with εr = 3.0 and h = 30 mils. The tuning of the center frequency and the passband transformation are done using silicon varactor diodes. In the 4‐pole single‐passband mode, a center frequency tuning of 1.0 to 1.4 GHz is achieved with 1‐dB bandwidths of 150 to 198 MHz. The 2‐pole dual‐band bandpass filter mode has the center frequency tuning of 1.0 to 1.29 GHz (low‐band) and 1.4 to 1.58 GHz (high‐band). The application areas are in wideband cognitive radios.
Cheolsoo Park
Professor
His research interests include machine learning, adaptive signal processing, computational neuroscience, and wearable technology.