High-speed signal power detection circuit

A radio frequency integrated circuit comprises:

• a receiver section operably coupled to convert inbound radio frequency signals into inbound intermediate frequency signals;
• transmitter section operably coupled to convert outbound intermediate frequency signals into outbound radio frequency signals;
• and
• transmit/receive switch operably coupled to connect either the receiver section or the transmitter section to an antenna, wherein the transmitter section includes:
• mixing module operably coupled to convert the outbound low intermediate frequency signal into a radio frequency signal;
• power amplifier operably coupled to amplify the radio frequency signal to produce an amplified radio frequency signal;
• bandpass filter operably coupled to filter the amplified radio frequency signal to produce the outbound radio frequency signal;
• and
• transmit signal strength indication module operably coupled to monitor transmit power of the power amplifier, the bandpass filter, or the transmit/receive switch, wherein the transmit signal strength indication module includes:
• an input coupling circuit operably to receive the amplified radio frequency signal, the outbound radio frequency signal, or a transmit radio frequency signal as an input signal and to convert the input signal into a first input and a rectifying input;
• a rectifying operation amplifier including:
• first input transistor operably coupled to receive the first input;
• second input transistor;
• rectifying transistor operably coupled to receive the rectifying input;
• current source operably coupled to provide a reference current to the first input transistor, second input transistor, and the rectifying transistor;
• first active input load transistor operably coupled to provide a first active load for the first input transistor and the rectifying transistor;
• second active input load transistor operably coupled to provide a second active load for the second transistor;
• active output load transistor operably coupled to mirror the reference current;
• and
• output transconductance stage operably coupled to the active load transistor and to the first input transistor and the rectifying transistor, wherein the output transconductance stage provides a rectified output representing a peak value of the signal;
• comparator operably coupled to compare the peak value of the signal with an output peak value to produce a comparison value;
• and
• charge pump operably coupled to convert the comparison value into a corresponding current that represents the output peak value.