Analog peak detection circuitry for radio receivers
First Claim
Patent Images
1. A radio receiver formed in an integrated circuit, comprising:
- a low noise amplifier (LNA) coupled to receive an RF signal from an antenna, the LNA for providing amplification of the RF signal in accordance with control commands;
a mixer coupled to receive an amplified RF signal from the LNA, the mixer for down converting the amplified RF signal into I and Q modulated channels;
an analog peak amplitude detection circuit further comprising;
log circuitry for producing an output characterized by the log(x), the log circuitry coupled to receive the I and Q modulated channels and for producing log(I) and log(Q) modulated channel signals;
dual input nodes coupled to receive the log(I) and log(Q) modulated channel signals from the log circuitry, one at each input of the dual input nodes;
a voltage follower configuration wherein an output signal of the analog peak amplitude detection circuit is a function of the sum of the log(I) and log(Q) modulated channel signals; and
gain control circuitry coupled to receive the output signal and to produce therefrom the control commands.
4 Assignments
0 Petitions
Accused Products
Abstract
A receiver portion of a radio includes an analog circuit for determining a peak amplitude in a way that eliminates or reduces the effects of frequency errors that are introduced by crystals within filters and other devices. A voltage follower and a current mirror in which a MOSFET coupled to an output node produces a voltage across its gate to source terminals whose value is a function of a sum of the gate to source voltages of two MOSFET devices that receive a logarithm of an I modulated channel and a logarithm of a Q modulated channel, respectively.
-
Citations
21 Claims
-
1. A radio receiver formed in an integrated circuit, comprising:
-
a low noise amplifier (LNA) coupled to receive an RF signal from an antenna, the LNA for providing amplification of the RF signal in accordance with control commands;
a mixer coupled to receive an amplified RF signal from the LNA, the mixer for down converting the amplified RF signal into I and Q modulated channels;
an analog peak amplitude detection circuit further comprising;
log circuitry for producing an output characterized by the log(x), the log circuitry coupled to receive the I and Q modulated channels and for producing log(I) and log(Q) modulated channel signals;
dual input nodes coupled to receive the log(I) and log(Q) modulated channel signals from the log circuitry, one at each input of the dual input nodes;
a voltage follower configuration wherein an output signal of the analog peak amplitude detection circuit is a function of the sum of the log(I) and log(Q) modulated channel signals; and
gain control circuitry coupled to receive the output signal and to produce therefrom the control commands. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. An analog peak amplitude detection circuit formed within a radio receiver for detecting a peak of a modulated signal, comprising:
-
log circuitry for producing a logarithm of an I modulated channel signal and of a Q modulated channel signal;
first and second input MOSFETs, each having a gate terminal, a source terminal and a drain terminal, the first input MOSFET coupled to receive the logarithm of the I modulated channel signal at the gate terminal of the first input MOSFET, and the second input MOSFET coupled to receive the logarithm of the Q modulated channel signal at the gate terminal of the second input MOSFET;
an output node of the analog peak amplitude detection circuit;
an output MOSFET having a gate terminal, a source terminal and a drain terminal wherein the drain terminal and the gate terminal of the output MOSFET are coupled to the output node of the analog peak amplitude detection circuit;
a current drain coupled to sink current from the source terminals of the first and second input MOSFETs and the output MOSFET; and
a current mirror coupled between a voltage source and the drain terminals of the first and second input MOSFETs and the drain terminal of the output MOSFET. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
-
-
17. A method for detecting a peak voltage in an analog circuit, comprising:
-
receiving a logarithm of an I modulated channel signal having a first amplitude at a gate terminal of a first input MOSFET, the first input MOSFET having a gate, a source and a drain terminal;
receiving a logarithm of a Q modulated channel signal having a second amplitude at a gate terminal of a second input MOSFET, the second input MOSFET having a gate, a source and a drain terminal; and
producing an output signal across an output MOSFET'"'"'s gate and source terminals wherein the output MOSFET'"'"'s gate terminal is coupled to an output node, the output signal having an amplitude that is a function of a sum of an amplitude of a signal formed across the gate to source terminals of the first and second input MOSFETs. - View Dependent Claims (18, 19, 20, 21)
-
Specification