Filter switching circuit having a shorter distance of connection for a higher frequency passband

A filter switching circuit comprising:

• a first amplifier formed on a printed circuit board;
• a second amplifier formed on said printed circuit board separately from said first amplifier, said second amplifier having an input end opposed to the output end of said first amplifier;
• a plurality of filters having different frequency passbands;
• and
• first and second groups of relays each having two fixed terminals and a switching terminal for connecting to one of the fixed terminals, the groups of relays being each formed by a plurality of relays for connecting one of said plurality of relays between the output end and the input end;
• wherein the relays of the first and second groups and the filters are arranged in parallel in an area between said first amplifier and said second amplifier on said printed circuit board so as to cross a straight line connecting the output end and the input end so that the filters are positioned between the first group of relays and the second group of relays, and one relay in the first group of relays and one relay in the second group of relays are arranged almost on said straight line while the switching terminals thereof are separately connected to the output end and the input end so that the other relays in each group of relays are connected in cascade to one fixed terminal of said one relay in each group of relays by connecting each switching terminal thereof to either fixed terminal, and between the other fixed terminals of two corresponding relays among the other relays in the groups of relays, each of the filters is connected, whereby the frequency passbands of filters having closer connections to the said one relay are sequentially higher increased.