X Band TX reject waveguide bandpass filter design for satellite communication systems

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2018
Çelebi, İrem
For several applications such as satellite communication, filters are required since antenna systems are operating as both receiving and transmitting. There is a possibility of leakage from transmit to the receive path in these kind of systems which needs to be isolated in order to protect equipments after filter. Low loss, high isolation and bandpass characteristics are desired for the filtering, which can be validated with waveguide filters. In this study, bandpass waveguide filter design operating in X-Band for satellite communication systems is investigated from the theory to validation. For this purpose, 13th order and 15th order shunt connected symmetrical iris waveguide filters are realized. Suitable flange type, theoretical synthesis procedure, optimization on dimensions, simulation comparisons of the realizable filter are inspected. Also, optimization and tuning work, that are unavoidable for this order of filters, are precisely searched. Results of different manufacturing techniques as screw connection, laser welding and brazing are examined. As a result, a bandpass filter passes signals between 7.25 GHz to 7.75 GHz and rejects signals after 7.9 GHz at least 70 dB is obtained. The filter has at least 17 dB return loss and 0.5 dB insertion loss in the passband region.

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Citation Formats
İ. Çelebi, “X Band TX reject waveguide bandpass filter design for satellite communication systems,” M.S. - Master of Science, Middle East Technical University, 2018.