Abstract
A novel ultra wideband (UWB) bandpass filter is presented, using a compact coupled microstrip/coplanar waveguide (CPW) structure. The filter comprises of a single CPW quarter-wavelength resonator which is coupled to two microstrip open-circuited stubs on the other side of a common substrate. The two microstrip open-circuited stubs, which are about a quarter-wave-length long at the center frequency, can function as two resonators with associated coupling arrangement to the CPW. This forms a very compact three-pole filter. The proposed filter also exhibits a quasi-elliptic function response, with one finite-frequency transmission zero closer to each side of the passband. Thus, a high selectivity is achieved using a small number of resonators, which leads to low insertion loss and group delay across the passband. The performance is predicated using EM simulations and verified experimentally. The experimental filter shows a fractional bandwidth of 90% at a center frequency of 6.4 GHz, with two observable transmission zeros (attenuation poles) at 1.95 and 10.36 GHz, respectively. Furthermore, it has a very small size only amounting to 0.25 by 0.08 guided wavelength at the center frequency. © 2007 IEEE.
Original language | English |
---|---|
Pages (from-to) | 184-186 |
Number of pages | 3 |
Journal | IEEE Microwave and Wireless Components Letters |
Volume | 17 |
Issue number | 3 |
DOIs | |
Publication status | Published - Mar 2007 |
Keywords
- Bandpass filters (BPFs)
- Coplanar waveguide (CPW)
- Microstrip
- Ultra wideband (UWB)