| 摘要 |
PURPOSE:To break the influence between transmission and receiving waves, by L (electromagnetic field) or C (electric field)-connecting filters for transmission and receiving and lines and setting the line length between filters and switches to an integer of lambda/14 for the purpose of stopping the transfer of signal energy to filters in attenuation bands of filters. CONSTITUTION:The output side of a transmission-side BPF9 is connected to a coaxial line l1 of electric length lambda/4 in L (electromagnetic field). This line l1 is connected to not only a main antenna 1 but also a coaxial line l3 of lambda/4 and a diode switch D1 connected in parallel to the line through a coaxial line l2 of electric length lambda/4. Meanwhile, a receiving-side band pass filter 10 has a pass frequency band different from that of the filter 9, and the input side is connected to a coaxial line l4 of electric length lambda/4 and the line l3 in C (electric field), and the line l4 is connected to a subantenna 3 through a diode switch D2 connected in parallel to the line. |
