USB Type-C power supply Can directly output 3.3V TTL signal. Usage:   USB port access 5V power supply (maximum 5.5V) When the output power needs to be measured. The left side is the RF input. The right side is the RF output When it is necessary to measure the reflected power. The left side is the RF output. The radio input is on the right. V: Detection (envelope) signal Logic: TTL logical signal output Vref point: comparator reference voltage The comparator reference voltage can be adjusted by a 3303W patch potentiometer When the detection voltage is lower than the reference voltage, the TTL output is low When the detection voltage is higher than the reference voltage, the TTL output is high. The green LED is a power indicator that lights up after the USB is inserted. The blue LED is the TTL output indicator, which lights up when the TTL output is high.   Application scenarios: bidirectional power amplifier (TR component) transceiver switching, power amplifier output standing wave protection, input-output monitoring, etc.