# US 7,610,029 B2 · Method for active Gm-C filter gain control > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,610,029 B2 - Document ID: US7610029B2 - Status: Granted - Kind: B2 - Application number: 11/394,682 - Filed: 2006-03-31 - Published: 2007-10-04 - Granted: 2009-10-27 - Earliest claimed: 2006-03-31 - Assignees: Broadcom Corporation - Inventors: Qiang Li - Web page: https://patentgrep.com/patent/US7610029B2 ## CPC - H04B 1/1027: {assessing signal quality or detecting noise/interference for the received signal} - H03G 9/12: having semiconductor devices - H03H 11/0472: {Current or voltage controlled filters} - H03K 17/6871: {the output circuit comprising more than one controlled field-effect transistor} - H04B: TRANSMISSION - H03G: CONTROL OF AMPLIFICATION - H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P) - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) ## Abstract An integrated circuit chip include a transmitter configured for transmitting an electromagnetic signal, a receiver configured for receiving an electromagnetic signal, and an amplifier operatively coupled to the receiver. The amplifier includes a plurality of variable-gain Gm-C filter stages connected in series and configured for selectively amplifying frequency components within a frequency bandwidth of the received electromagnetic signal. ## Claims ### Claim 1 An integrated circuit chip comprising: a transmitter configured for transmitting an electromagnetic signal; a receiver configured for receiving an electromagnetic signal; an amplifier operatively coupled to the receiver, wherein the amplifier comprises a plurality of variable-gain Gm-C filter stages connected in series and configured for selectively amplifying frequency components within a frequency bandwidth of the received electromagnetic signal; wherein an input stage of at least one of the variable gain Gm-C filter stages comprises a first transconductor and a second transconductor, both of the transconductors having their inputs and outputs connected in parallel; wherein a gain of the first transconductor is more than about 8 dB greater than a gain of the second transconductor. ### Claim 2 (depends on 1) The integrated circuit chip of claim 1, wherein the integrated circuit chip comprises a wireless transceiver. ### Claim 3 (depends on 1) The integrated circuit chip of claim 1, wherein the gain of the second transconductor is adapted to be varied continuously, and wherein the first transconductor is adapted to be operatively coupled to, and operatively decoupled from, the at least one variable gain Gm-C filter stage. ### Claim 4 (depends on 3) The integrated circuit chip of claim 3 farther comprising a variable resistor operably connected between an output of the second transconductor and ground, the resistance of the variable resistor being variable, such that the frequency bandwidth when the first transconductor is coupled is approximately equal to the frequency bandwidth when the first transconductor is decoupled. ### Claim 5 (depends on 1) The integrated circuit chip of claim 1, wherein the input stage of the at least one variable gain Gm-C filter stage comprises a third transconductor having an input operatively connected to inputs of the first transconductor and to the second transconductor and having an output that is operatively unconnected from the outputs of the first and second transconductors. ### Claim 6 (depends on 5) The integrated circuit chip of claim 5, wherein the third transconductor is adapted to be switched off when the first transconductor is in a conducting state and to be switched on when the first transconductor is in a non-conducting state. ### Claim 7 (depends on 1) The integrated circuit chip of claim 1, wherein an input stage of each of the variable-gain Gm-C filter stages comprises a first transconductor and a second transconductor, both of the transconductors having their inputs and outputs operatively connected in parallel, where the first transconductor of each input stage is adapted to be stepwise set to achieve a range of gains values. ### Claim 8 (depends on 7) The integrated circuit chip of claim 7, wherein the range of gain values is greater than about 10 dB. ### Claim 9 A method of processing a signal in a wireless receiver integrated circuit chip, the method comprising: receiving an electromagnetic signal; amplifying the received signal in a plurality of variable-gain Gm-C filter stages connected in series and configured for selectively amplifying frequency components of the received electromagnetic signal, wherein an input stage of at least one variable gain Gm-C filter stage comprises a first transconductor and a second transconductor, both of the transconductors having their inputs and outputs connected in parallel and wherein a gain of the first transconductor is greater than a gain of the second transconductor. ### Claim 10 (depends on 9) The method of claim 9, further comprising varying the gain of the first transconductor discretely. ### Claim 11 (depends on 10) The method of claim 10, further comprising varying the gain of the second transconductor continuously. ### Claim 12 (depends on 9) The method of claim 9, wherein the input stage of the at least one variable gain Gm-C filter stage comprises a third transconductor having an input operatively connected to inputs of the first transconductor and to the second transconductor and having an output that is operatively unconnected from the outputs of the first and second transconductors, and further comprising switching off the third transconductor when the first transconductor is in a conducting state and switching on the third transconductor when the first transconductor is in a non-conducting state. ### Claim 13 An integrated circuit chip comprising: a transmitter configured for transmitting an electromagnetic signal; a receiver configured for receiving an electromagnetic signal; an amplifier operatively coupled to the receiver, wherein the amplifier comprises a plurality of variable-gain Gm-C filter stages connected in series and configured for selectively amplifying frequency components within a frequency bandwidth of the received electromagnetic signal, wherein an input stage of at least one variable gain Gm-C filter stage comprises a first transconductor and a second transconductor, both of the transconductors having their inputs and outputs connected in parallel; and a variable resistor operably connected between an output of the second transconductor and ground, wherein the gain of the second transconductor is adapted to be varied continuously, and wherein the first transconductor is adapted to be operatively coupled to, and operatively decoupled from, the at least one variable gain Gm-C filter stage, and wherein the resistance of the variable resistor is variable, such that the frequency bandwidth when the first transconductor is coupled to the at least one variable gain Gm-C filter state is approximately equal to the frequency bandwidth when the first transconductor is decoupled from the at least one variable gain Gm-C filter state. ### Claim 14 (depends on 13) The integrated circuit chip of claim 13, wherein the input stage of the at least one variable gain Gm-C filter stage comprises a third transconductor having an input operatively connected to inputs of the first transconductor and to the second transconductor and having an output that is operatively unconnected from the outputs of the first and second transconductors. ### Claim 15 (depends on 14) The integrated circuit chip of claim 14, wherein the third transconductor is adapted to be switched off when the first transconductor is in a conducting state and to be switched on when the first transconductor is in a non-conducting state. ### Claim 16 (depends on 13) The integrated circuit chip of claim 13, wherein an input stage of each of the variable-gain Gm-C filter stages comprises a first transconductor and a second transconductor, both of the transconductors having their inputs and outputs operatively connected in parallel, where the first transconductor of each input stage is adapted to be stepwise set to achieve a range of gains values. ### Claim 17 (depends on 16) The integrated circuit chip of claim 16, wherein the range of gain values is greater than about 10 dB. ### Claim 18 (depends on 13) The integrated circuit chip of claim 13, wherein the integrated circuit chip comprises a wireless transceiver. ### Claim 19 (depends on 13) The integrated circuit chip of claim 13, wherein a gain of the first transconductor is more than about 8 dB greater than a gain of the second transconductor. ### Claim 20 An integrated circuit chip comprising: a transmitter configured for transmitting an electromagnetic signal; a receiver configured for receiving an electromagnetic signal; and an amplifier operatively coupled to the receiver, wherein the amplifier comprises a plurality of variable-gain Gm-C filter stages connected in series and configured for selectively amplifying frequency components within a frequency bandwidth of the received electromagnetic signal, wherein an input stage of at least one variable gain Gm-C filter stage comprises a first transconductor and a second transconductor, both of the transconductors having their inputs and outputs connected in parallel, and third transconductor having an input operatively connected to inputs of the first transconductor and to the second transconductor and having an output that is operatively unconnected from the outputs of the first and second transconductors. ### Claim 21 (depends on 20) The integrated circuit chip of claim 20, wherein the third transconductor is adapted to be switched off when the first transconductor is in a conducting state and to be switched on when the first transconductor is in a non-conducting state. ### Claim 22 (depends on 1) The integrated circuit chip of claim 1, wherein an input stage of each of the variable-gain Gm-C filter stages comprises a first transconductor and a second transconductor, both of the transconductors having their inputs and outputs operatively connected in parallel, where the first transconductor of each input stage is adapted to be stepwise set to achieve a range of gains values. ### Claim 23 (depends on 22) The integrated circuit chip of claim 22, wherein the range of gain values is greater than about 10 dB. ### Claim 24 (depends on 20) The integrated circuit chip of claim 20, wherein a gain of the first transconductor is more than about 8 dB greater than a gain of the second transconductor. ### Claim 25 (depends on 20) The integrated circuit chip of claim 20, wherein the gain of the second transconductor is adapted to be varied continuously, and wherein the first transconductor is adapted to be operatively coupled to, and operatively decoupled from, the at least one variable gain Gm-C filter stage. ### Claim 26 (depends on 20) The integrated circuit chip of claim 20 further comprising a variable resistor operably connected between an output of the second transconductor and ground, the resistance of the variable resistor being variable, such that the frequency bandwidth when the first transconductor is coupled is approximately equal to the frequency bandwidth when the first transconductor is decoupled.