A Diplexer based on Hybrid Cavity and Microstrip Structure
Keywords:
Cavity, diplexer, hybrid structure, microstripAbstract
This paper presents a high selective diplexer with hybrid filters, which is composed by dual-mode microstrip resonators with metallic coaxial shielding cases of RF module. By utilizing vertical space above microstrip circuits which greatly saves space, an additional pair of transmission pole and zero are hereby added in the passband and stopband, respectively. The proposed structure provides high quality-factors to enhance frequency selectivity. For demonstration, a diplexer prototype is designed and fabricated at the center frequencies (CF) of 2.40 and 3.45 GHz with a 3-dB passband bandwidth of 200 MHz. The measured insertion losses (IL) are 1.45 dB and 1.61 dB in the lower and upper passbands respectively. The output isolation between two channels is measured greater than 32 dB.
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References
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