Detection circuit and detection method
View Patent ↗A detection circuit includes a bias circuit configured to generate a first bias voltage and a second bias voltage. The detection circuit further includes a storage device configured to store a detection value corresponding to an amplitude of a radio frequency signal received at a detector input. A series connection of a first diode element and a second diode element includes first tap to receive the first bias voltage and the radio frequency signal, a second tap which is coupled to a connection node of the first and the second diode element to receive the second bias voltage and a third tap to provide the detection value.
1. A detection circuit, comprising:
a detector input configured to receive a time varying detection signal;
a detector output;
a capacitive output element coupled to the detector output;
a bias circuit comprising a first bias output configured to provide a first bias voltage and a second bias output configured to provide a second bias voltage;
a transistor having a control terminal coupled to the detector input and a first terminal configured to be coupled to a supply voltage, wherein the control terminal is coupled to the first bias output and configured to receive a first intermediate signal as a function of the first bias voltage and the detection signal;
a coupling capacitance element coupled between the control terminal and the first terminal of the transistor, and configured to pass the time varying detection signal from the detector input to the first terminal and concurrently block a DC voltage from passing therethrough, thereby operating as a high pass filter;
a rectifying element comprising a first terminal coupled to a second terminal of the transistor and to the second bias output, and a second terminal coupled to the capacitive output element.
2. The detection circuit of claim 1 , wherein the rectifying element comprises a diode-connected transistor having a control terminal coupled to the second bias output, a first terminal coupled to the second terminal of the transistor, and a second terminal coupled to the capacitive output element, wherein the control terminal and the first terminal are coupled together.
3. A detection circuit, comprising:
a detector input configured to receive a time varying detection signal;
a detector output;
a capacitive output element coupled to the detector output;
a bias circuit comprising a first bias output configured to provide a first bias voltage and a second bias output configured to provide a second bias voltage;
a first rectifying element coupled between the first bias output and the second bias output;
a second rectifying element coupled between the second bias output and the capacitive output element;
wherein the detector input is coupled to one of the first bias output and the second bias output; and
a control unit coupled to the detector output, and configured to vary the first bias voltage based on an output voltage at the detector output.
4. The detection circuit of claim 3 , wherein the first rectifying element comprises a diode having an anode coupled to the first bias output, and a cathode coupled to the second bias output.
5. The detection circuit of claim 3 , wherein the first rectifying element comprises a diode-connected transistor having a control terminal and a first terminal coupled together and coupled to the first bias output, and a second terminal coupled to the second bias output.
6. The detection circuit of claim 3 , wherein the second rectifying element comprises a diode having an anode coupled to the second bias output, and a cathode coupled to the detector output.
7. The detection circuit of claim 3 , wherein the second rectifying element comprises a diode-connected transistor having a control terminal and a first terminal coupled together and coupled to the second bias output, and a second terminal coupled to the detector output.
8. The detection circuit of claim 3 , further comprising an input capacitive element coupled between the detector input and the second bias output.