The block diagram of the Automatic Frequency Controller system

Specifications

Parameter Value
 Center Frequency  9.3GHz – can be set
 Span  100MHz,15MHz (9280-9295 MHz) – can be set
 Resolution  100kHz? 10kHz – can be set
 Input trigger  Divide trigger for AFC
 Output  Analog Signal (-5 to 5V), Ethernet
 Input Power (RF)  0 dBm
 Full span delay  ~6 sec

Hardware Block Diagram

X-Band Frequency Counter

The X-band Frequency Counter aims to assist in the Automatic Frequency Controller (AFC) system. The phase detector, which compares the forward and reflected waves of the microwave signal, is used to tune the frequency of the magnetron. However, the large temperature drift of the magnetron causes the frequency to deviate from the operation range of the phase detector (fc± 4MHz) especially during start-up. The frequency counter, which has larger operation range (fc± 50MHz), will send signals to tune the magnetron into the phase detector operation range. After the magnetron frequency has been tuned to fc, the turning control is passed to the phase detector.