| 摘要 |
PURPOSE:To attain stable hopping control by decoding a transponder number at rise point of a burst enable signal to select a corresponding local oscillation frequency and to switch a polarized wave thereby detecting a parity error. CONSTITUTION:A 4-bit address signal is inputted to a latch circuit 23 together with an enable signal, an address code is latched by a rise point of the enable signal and latched till the rise of the next enable signal. On the other hand, the address signal is inputted to a parity bit and parity checker 25, latched in a latch circuit 26 and its output is inputted to an AND gate 27 together with the latch output of an address code. When no parity error exists, the address code of the latch circuit 23 is inputted to a decoder 28 as it is to operate a plarized wave switching circuit 14 and a local oscillation circuit 12 to send a required frequency and a polarized wave. If a parity error takes place, a code 0 is outputted from the decoder 28, an FF 30 is inverted and an alarm output is sent. |
