In accordance with an embodiment, an envelope detector includes a first transistor having a first current conduction terminal coupled to a first connection node; a second current conduction terminal coupled to an intermediate node; and a control terminal coupled the signal input node and to a biasing node; a second transistor having a first current conduction terminal coupled to the intermediate node; a second current conduction terminal coupled to a second connection node; and a control terminal coupled to the biasing node; and a first temperature compensating transistor that is diode-connected and coupled between a compensation output node and the biasing node. The second connection node is coupled to the compensation output node and the first connection node is coupled to a detector output.

A detector circuit being part of a Radio Frequency Identification (RFID) device is provided, including: a bias current generator circuit configured to generate an output bias current that is proportional to the square of a temperature-dependent input current; first and second Field-Effect Transistor (FET) devices; at least one of the first and the second FET devices is biased by means of the output bias current of the bias current generator circuit so that FET device(s) operates in a sub-threshold region; an incoming Radio Frequency (RF) signal being coupled into at least one of the first and the second FET devices; a current source configured to generate a variable threshold current; and a comparator configured to determine, based on the variable threshold current and the incoming RF signal, whether a value of the incoming RF signal exceeds a threshold value.

A wireless receiver and a wireless reception method provide: to determine a gain based on a first resistor having a first temperature characteristic and a second resistor having a second temperature characteristic different from the first resistance; to output an output of the first resistor and an output of the second resistor, or a ratio between the output of the first resistor and the output of the second resistor; and to switches the gain of the first circuit based on the outputs or the ratio between the outputs.

The present invention relates to a detector circuit (10) being part of an RFID-device, and comprising: a bias current generator circuit (20) configured to generate an output bias current that is proportional to the square of a temperature-dependent input current, a first and a second FET-devices (21, 22), at least one of the first and the second FET-devices (21, 22) is biased by means of the output bias current of the bias current generator circuit (20) so that it operates in the sub-threshold region, an incoming RF-signal is coupled into at least one of the first and the second FET-devices, a current source (18) for generating a variable threshold current, and a comparator (19) for determining, on the basis of the variable threshold current and the incoming RF-signal, whether the value of the incoming RF-signal exceeds a threshold value.

A wireless receiver and a wireless reception method provide: to determine a gain based on a first resistor having a first temperature characteristic and a second resistor having a second temperature characteristic different from the first resistance; to output an output of the first resistor and an output of the second resistor, or a ratio between the output of the first resistor and the output of the second resistor; and to switches the gain of the first circuit based on the outputs or the ratio between the outputs.