Radio frequency power limiter with reflected power detection
A radio frequency (RF) power limiter includes an input direct current (DC) block, an output DC block, a limiter diode, a RF choke, and a test diode. A first terminal of the limiter diode is coupled to a node between the input DC block and the output DC block, and a second terminal of the limiter diode is coupled to an electrical ground. A first terminal of the RF choke is coupled to the node between the input DC block and the output DC block so that the first terminal of the RF choke is coupled to the first terminal of the limiter diode. A first terminal of the test diode is coupled to the second terminal of the RF choke, and a second terminal of the test diode is coupled to the electrical ground.
1. A radio frequency (RF) power limiter, comprising:
an input direct current (DC) block;
an output DC block;
a limiter diode having a first terminal and a second terminal, the first terminal of the limiter diode being coupled to a node between the input DC block and the output DC block, and the second terminal of the limiter diode being coupled to an electrical ground;
a RF choke having a first terminal and a second terminal, the first terminal of the RF choke being coupled to the node between the input DC block and the output DC block so that the first terminal of the RF choke is coupled to the first terminal of the limiter diode;
a test diode having a first terminal and a second terminal, wherein the first terminal of the test diode is coupled to the second terminal of the RF choke, the second terminal of the test diode is coupled to the electrical ground, and a forward voltage of the test diode is indicative of whether current is flowing through the limiter diode; and
a detection circuit configured to detect whether current is flowing through the limiter diode based on the forward voltage.
2. The RF power limiter of claim 1 , wherein the input DC block comprises at least one input capacitor, and the output DC block comprises at least one output capacitor.
3. The RF power limiter of claim 1 , wherein the limiter diode comprises a PIN diode.
4. The RF power limiter of claim 1 , wherein the RF choke comprises at least one inductor.
5. The RF power limiter of claim 1 , wherein the test diode comprises a Schottky diode.
6. The RF power limiter of claim 1 , wherein the detection circuit includes an analog-to-digital converter (ADC) configured to quantize the forward voltage.
7. The RF power limiter of claim 1 , wherein the detection circuit includes an operational amplifier configured to generate an output signal based on the forward voltage.
8. The RF power limiter of claim 7 , wherein the detection circuit further includes a light-emitting diode (LED) driven by the output signal.
9. A communication system, comprising:
a receiver;
an antenna configured to detect wireless signals for the receiver; and
one or more radio frequency (RF) power limiters coupled between the antenna and the receiver, wherein a RF power limiter of the one or more RF power limiters includes:
an input direct current (DC) block;
an output DC block;
a limiter diode having a first terminal and a second terminal, the first terminal of the limiter diode being coupled to a node between the input DC block and the output DC block, and the second terminal of the limiter diode being coupled to an electrical ground;
a RF choke having a first terminal and a second terminal, the first terminal of the RF choke being coupled to the node between the input DC block and the output DC block so that the first terminal of the RF choke is coupled to the first terminal of the limiter diode;
a test diode having a first terminal and a second terminal, wherein the first terminal of the test diode is coupled to the second terminal of the RF choke, the second terminal of the test diode is coupled to the electrical ground, and a forward voltage of the test diode is indicative of whether current is flowing through the limiter diode; and
a detection circuit configured to detect whether current is flowing through the limiter diode based on the forward voltage.
10. The communication system of claim 9 , wherein the input DC block comprises at least one input capacitor, and the output DC block comprises at least one output capacitor.
11. The communication system of claim 9 , wherein the limiter diode comprises a PIN diode.
12. The communication system of claim 9 , wherein the RF choke comprises at least one inductor.
13. The communication system of claim 9 , wherein the test diode comprises a Schottky diode.
14. The communication system of claim 9 , wherein the detection circuit includes an analog-to-digital converter (ADC) configured to quantize the forward voltage.
15. The communication system of claim 9 , wherein the detection circuit includes an operational amplifier configured to generate an output signal based on the forward voltage.
16. The communication system of claim 15 , wherein the detection circuit further includes a light-emitting diode (LED) driven by the output signal.