Power detector for detecting radio frequency power output
A power detector for measuring the radio frequency (RF) power of RF signals generated by a transmitter or a power amplifier of a transmitter is connected between two diodes of electrostatic discharge (ESD) circuitry that is connected to a signal pathway utilized to transmit the RF signals.
1. An electronic device, comprising:
a transmitter;
an antenna coupled to the transmitter;
electrostatic discharge (ESD) circuitry coupled to the transmitter and the antenna at a node, the ESD circuitry comprising a plurality of diodes; and
a power detector coupled to the ESD circuitry between a first diode of the plurality of diodes and a second diode of the plurality of diodes, the first diode coupled to a voltage supply or ground, and the second diode coupled between the first diode and the node.
2. The electronic device of claim 1 , wherein the power detector comprises
a capacitor configured to receive electrical current from the ESD circuitry,
clamp circuitry coupled to the capacitor and configured to generate a biased current by adding direct current (DC) bias to a current received from the capacitor, and
rectifying circuitry coupled to the clamp circuitry, the rectifying circuitry configured to receive the biased current from the clamp circuitry and to generate a DC electrical current from the biased current.
3. The electronic device of claim 2 , comprising a reference line coupled to the voltage supply and configured to output a reference electrical current.
4. The electronic device of claim 3 , comprising a differential amplifier configured to
receive the DC electrical current from the rectifying circuitry,
receive the reference electrical current from the reference line, and
generate a differential output indicative of a difference between a first voltage of the DC electrical current and a second voltage of the reference electrical current.
5. The electronic device of claim 2 , comprising a first switch coupling the clamp circuitry and the rectifying circuitry and configurable to prevent the rectifying circuitry from receiving the biased current from the clamp circuitry.
6. The electronic device of claim 1 , wherein the plurality of diodes comprises at least one diode coupled between the node and the ground and at least one diode coupled between the voltage supply and the node.
7. The electronic device of claim 1 , comprising a matching network coupled between the transmitter and the ESD circuitry.
8. The electronic device of claim 7 , comprising a second switch coupling the matching network and the ESD circuitry, the second switch configurable to prevent the ESD circuitry from receiving electrical current from the matching network.
9. The electronic device of claim 4 , wherein the reference line comprises
a third switch coupling the voltage supply and the differential amplifier, the third switch configurable to prevent the differential amplifier from receiving the reference electrical current,
a variable resistor coupled between the voltage supply and the third switch, and
second rectifying circuitry disposed along the reference line between the third switch and the differential amplifier, the second rectifying circuitry configured to generate the reference electrical current.
10. Wireless transmission circuitry, comprising:
a transmitter configured to transmit a radio frequency (RF) signal;
an antenna coupled to the transmitter and configured to receive the RF signal;
a matching network coupled between the transmitter and the antenna;
electrostatic discharge (ESD) circuitry coupled to the matching network and the antenna at a node, the ESD circuitry comprising a plurality of diodes; and
a power detector configured to detect a voltage or current of the RF signal, the power detector coupled to the ESD circuitry between a first diode of the plurality of diodes and a second diode of the plurality of diodes, the first diode coupled to a voltage supply or ground, and the second diode coupled between the first diode and the node.
11. The wireless transmission circuitry of claim 10 , wherein the power detector comprises
a capacitor configured to receive electrical current from the ESD circuitry,
clamp circuitry coupled to the capacitor and configured to generate a biased current by biasing a current received from the capacitor, and
rectifying circuitry coupled to the clamp circuitry, the rectifying circuitry configured to receive the biased current from the clamp circuitry and to generate a direct current (DC) electrical current from the biased current.
12. The wireless transmission circuitry of claim 11 , wherein the rectifying circuitry comprises a metal-oxide-semiconductor (MOS) diode, a resistor, and a capacitor.
13. The wireless transmission circuitry of claim 11 , comprising:
a reference line coupled to the voltage supply and configured to output a reference electrical current; and
a differential amplifier configured to
receive the DC electrical current from the rectifying circuitry,
receive the reference electrical current from the reference line, and
generate a differential output indicative of a difference between a first voltage of the DC electrical current and a second voltage of the reference electrical current.
14. The wireless transmission circuitry of claim 10 , wherein the plurality of diodes comprises three or more diodes.
15. The wireless transmission circuitry of claim 10 , comprising a first switch coupling the matching network and the ESD circuitry, the first switch configurable to prevent the ESD circuitry from receiving electrical current from the matching network.
16. The wireless transmission circuitry of claim 11 , comprising a second switch coupling the clamp circuitry and the rectifying circuitry and configurable to prevent the rectifying circuitry from receiving the biased current from the clamp circuitry.
17. A power detector, comprising:
a capacitor configured to receive electrical current from electrostatic discharge (ESD) circuitry, the capacitor coupled to a first diode of the ESD circuitry and a second diode of the ESD circuitry, the ESD circuitry coupled to a transmitter and an antenna at a node, the first diode coupled to a voltage supply or ground, and the second diode coupled between the first diode and the node;
clamp circuitry coupled to the capacitor and configured to generate a biased current by adding a direct current (DC) bias to a current received from the capacitor;
rectifying circuitry coupled to the clamp circuitry, the rectifying circuitry configured to receive the biased current from the clamp circuitry and to generate a direct current (DC) electrical current from the biased current; and
a first switch coupling the clamp circuitry and the rectifying circuitry and configurable to prevent the rectifying circuitry from receiving the biased current from the clamp circuitry.
18. The power detector of claim 17 , wherein
the clamp circuitry comprises one or more resistors, and
the rectifying circuitry comprises a diode, a resistor, and a second capacitor.
19. The power detector of claim 18 , comprising:
a reference line coupled to the voltage supply and configured to output a reference electrical current; and
a differential amplifier configured to
receive the DC electrical current from the rectifying circuitry,
receive the reference electrical current from the reference line, and
generate a differential output indicative of a difference between a first voltage of the DC electrical current and a second voltage of the reference electrical current.
20. The power detector of claim 19 , wherein the reference line comprises
a second switch coupling the voltage supply and the differential amplifier, the second switch configurable to prevent the differential amplifier from receiving the reference electrical current,
a variable resistor coupled between the voltage supply and the second switch, and
second rectifying circuitry disposed along the reference line between the second switch and the differential amplifier, the second rectifying circuitry configured to generate the reference electrical current.