Design Of Divider/Combiner With High Power And High Isolation

The side lobes and gain of the antenna array are influenced by the magnitude distribution of the feed network which is the key in the design of antenna arrays. Parallel and series feed network are the main methods of feeding antenna array. Parallel feed network can realize equal magnitude and phase distributions easily ,but its shortcomings are large size and high insertion loss. Series feed network is small in size and low in insertion loss, but its bandwidth is limited. The mismatch of antenna ports can cause feed network unable to provide the designed magnitude distribution, increase the side lobes and reduce the gain of the antenna array. Therefore the influence of the reflection on magnitude distributions should be as low as possible.In view of the problems above, a new microstrip power divider with equal magnitude and phase has been designed in this dissertation. Its advantages are small size, low insertion loss and high isolation between output ports. This power divider can be used as a feed line for the antenna array so that the reflection caused by the mismatch of an antenna element doesn't affect other elements and the feed magnitude distribution satisfies the requirement.Generally the gain and the power capacity of a single amplifier are limited, it is common to input the outputs of multiple amplifiers into a combiner to increase the output power. In order to improve the reliability of the power combining network, the conditions of match of ports and high isolation between ports should be satisfied. Most present power combiners adopt rectangular or circular cylindrical resonator and lossless network with coaxial ports. The isolation and matching between ports in a lossless network cannot exist simultaneously. When the combiner is connected to the amplifier in the waveguide, the size and insertion loss are increased due to the connector between them.In view of the problems above, a new high power and high isolation combiner has been designed. Its power capacity has been analyzed in this dissertation. Its characteristics are adopting waveguide ports so as to realize the match of ports and isolation between ports simultaneously. Therefore the size and insertion loss of the combiner are reduced and the reliability of the combiner is improved.