This letter presents a miniaturized dual-mode microstrip bandpass filter with the right crossed slots. The right crossed slots perturb and reduce the fundamental resonant frequency, but the second resonance is not affected. Therefore, the second resonance will be effectively higher than 2f/sub o/, where f/sub o/ is the fundamental frequency. Since the fundamental frequency is lower, the bandpass filter is smaller than the conventional filter. The proposed filter shows a 4.4% fractional bandwidth at 1.595GHz with a return loss of better than 10dB and an insertion loss of less than 2.5dB, while the second passband is located around 2.88f/sub o/= 4.6GHz. Compared with the conventional square patch filter, the proposed filter also shows a 58% size reduction.
[1]
Lei Zhu,et al.
Miniaturized dual-mode bandpass filter using inductively loaded cross-slotted patch resonator
,
2005
.
[2]
Ke Wu,et al.
New planar dual-mode filter using cross-slotted patch resonator for simultaneous size and loss reduction
,
1999
.
[3]
Raafat R. Mansour,et al.
Design of superconductive multiplexers using single-mode and dual-mode filters
,
1994
.
[4]
Jia-Sheng Hong,et al.
Microstrip filters for RF/microwave applications
,
2001
.
[5]
Ban-Leong Ooi,et al.
A modified microstrip circular patch resonator filter
,
2002
.