RF detector with double balanced linear mixer and corresponding method of operation

A method of operating a radio frequency detector, wherein the radio frequency detector comprises a local oscillator path, a radio frequency path, a mixer, and a filter, wherein the local oscillator path comprises a first buffer and sine-to-square wave converter, and wherein the radio frequency path comprises a second buffer, the method comprising:

• detecting a radio frequency input signal within a substrate processing system;
• receiving a first radio frequency signal at the first buffer, wherein the first radio frequency signal is based on the radio frequency input signal;
• converting a sine wave of the first radio frequency signal to a square wave via the sine-to-square wave converter and outputting a local oscillator signal having the square wave;
• receiving a second radio frequency signal at the second buffer and outputting a radio frequency output signal, wherein the second radio frequency signal is based on the radio frequency input signal;
• generating an intermediate frequency signal via the mixer based on the local oscillator signal and the radio frequency output signal;
• and
• filtering the intermediate frequency signal via the filter to generate a direct current signal, wherein the direct current signal is representative of the second radio frequency signal.

A radio frequency detector comprising:

• a buffer to receive a first radio frequency signal, wherein the first radio frequency signal is generated based on a radio frequency input signal received by the radio frequency detector, and wherein the radio frequency input signal is detected by the radio frequency detector within a substrate processing system;
• a first filter to filter an output of the buffer;
• an amplifier to, based on an output of the filter, generate a differential output including a second radio frequency signal and a third radio frequency signal;
• a local oscillator path comprising a sine-to-square wave converter to convert a sine wave of the second radio frequency signal to a square wave and output a local oscillator signal having the square wave;
• a radio frequency path comprising a delay circuit, wherein the delay circuit is to receive the third radio frequency signal and output a radio frequency output signal;
• a double balanced mixer or a linear mixer to generate an intermediate frequency signal based on the local oscillator signal and the radio frequency output signal;
• and
• a second filter to filter the intermediate frequency signal to generate a direct current signal, wherein the direct current signal is representative of the second radio frequency signal.