# US 6,501,331 B2 · Multi-band amplifier > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,501,331 B2 - Document ID: US6501331B2 - Status: Granted - Kind: B2 - Application number: 09/821,177 - Filed: 2001-03-29 - Published: 2001-08-09 - Granted: 2002-12-31 - Earliest claimed: 1996-06-03 - Assignees: Anadigics, Inc. - Inventors: Aharon Adar - Web page: https://patentgrep.com/patent/US6501331B2 ## CPC - H03F 1/0261: {with control of the polarisation voltage or current, e.g. gliding Class A} - H03F 3/1935: {with junction-FET devices} - H03F 3/24: of transmitter output stages - H03F 3/72: Gated amplifiers, i.e. amplifiers which are rendered operative or inoperative by means of a control signal - H04B 1/0483: {Transmitters with multiple parallel paths} - H04B 1/406: {with more than one transmission mode, e.g. analog and digital modes} - H03F 2200/111: the amplifier being a dual or triple band amplifier, e.g. 900 and 1800 MHz, e.g. switched or not switched, simultaneously or not - H03F 2200/39: Different band amplifiers are coupled in parallel to broadband the whole amplifying circuit - H03F 2200/429: Two or more amplifiers or one amplifier with filters for different frequency bands are coupled in parallel at the input or output - H03F 2200/432: Two or more amplifiers of different type are coupled in parallel at the input or output, e.g. a class D and a linear amplifier, a class B and a class A amplifier - H03F 2203/7206: the gated amplifier being switched on or off by a switch in the bias circuit of the amplifier controlling a bias voltage in the amplifier - H03F 2203/7215: the gated amplifier being switched on or off by a switch at the input of the amplifier - H03F 2203/7221: the gated amplifier being switched on or off by a switch at the output of the amplifier - H03F 2203/7227: the gated amplifier being switched on or off by a switch in the supply circuit of the amplifier - H03F 2203/7236: the gated amplifier being switched on or off by putting into parallel or not, by choosing between amplifiers by (a ) switch(es) - H04B 1/005: {adapting radio receivers, transmitters andtransceivers for operation on two or more bands, i.e. frequency ranges} - H04B 2001/0408: {with power amplifiers} - H03F: AMPLIFIERS - H04B: TRANSMISSION ## Abstract A GaAs MMIC dual-band amplifier for wireless communications is disclosed for operation at either the 800 MHz or the 1900 MHz band and it provides desired gain and input and output impedance. Switching impedance networks are used at the input and output of the amplifier to provide matching input impedance and desired output impedance for operation in the two bands. Switching impedance networks are also used between any successive stages of the amplifier to provide proper interstage impedance. The dual band amplifier includes a bias control circuit which biases the amplifier to operate in A, B, AB or C mode. The amplifier can be used for the AMPS 800 or the GSM 900 operation or any other cellular operation such as the PCS 1900 and the it can be switched between the two operations by simply applying a proper control signal to the amplifier. ## Claims ### Claim 1 A multi-band amplifier circuit comprising: a plurality of amplifiers, each amplifier comprising at least one amplifying stage, being configurable to receive an input signal within a particular frequency band, and forming part of a monolithic integrated circuit; a plurality of impedance matching networks, each impedance matching network being coupled to a corresponding one of the plurality of amplifiers, and each impedance matching network providing a predetermined impedance within the frequency band for the corresponding amplifier, wherein at least a portion of each of the plurality of impedance matching networks also forms part of the monolithic integrated circuit; and a control circuit coupled to each of the plurality of amplifiers for selectively enabling one of the amplifiers and disabling the remaining amplifiers in response to at least one control signal. ### Claim 2 (depends on 1) The multi-band amplifier circuit of claim 1 wherein each of the plurality of impedance matching networks also forms part of the monolithic integrated circuit. ### Claim 3 (depends on 1) The multi-band amplifier circuit of claim 1 wherein the control circuit also forms part of the monolithic integrated circuit. ### Claim 4 (depends on 1) The multi-band amplifier circuit of claim 1 wherein each impedance matching network is coupled to an input of the corresponding amplifier to provide a predetermined input impedance within the frequency band for the corresponding amplifier. ### Claim 5 (depends on 4) The multi-band amplifier circuit of claim 4 wherein each predetermined input impedance approximately matches a source impedance for the input signal of the corresponding amplifier. ### Claim 6 (depends on 1) The multi-band amplifier circuit of claim 1 wherein each impedance matching network is coupled to an output of the corresponding amplifier to provide a predetermined output impedance within the frequency band for the corresponding amplifier. ### Claim 7 (depends on 1) The multi-band amplifier circuit of claim 1 wherein each amplifier comprises a plurality of amplifying stages arranged as a cascade, and wherein each amplifier further comprises at least one interstage impedance matching network coupled between two successive amplifying stages, wherein each interstage impedance matching network provides a predetermined interstage impedance within the frequency band for the corresponding amplifier. ### Claim 8 (depends on 7) The multi-band amplifier circuit of claim 7 wherein the interstage impedance is such that an output impedance of one of the successive amplifying stages approximately matches the input impedance of the other of the successive amplifying stages within the frequency band for the corresponding amplifier. ### Claim 9 (depends on 1) The multi-band amplifier circuit of claim 1 wherein the frequency band for one amplifier is near 800 MHz and the frequency band for another amplifier is near 1900 MHz. ### Claim 10 (depends on 1) The multi-band amplifier circuit of claim 1 wherein, when enabling one of the amplifiers, the control circuit further provides a predetermined bias to bias the enabled amplifier in a desired mode of operation. ### Claim 11 (depends on 10) The multi-band amplifier circuit of claim 10 wherein the desired mode of amplifier operation is one of: class A, B, AB, or C operation. ### Claim 12 A multi-band amplifier circuit comprising: a plurality of amplifiers, each amplifier comprising an input, an output, and at least one amplifying stage, being configurable to receive an input signal within a particular frequency band, and forming part of a monolithic integrated circuit; a plurality of input impedance networks, each input impedance network being coupled to the input of a corresponding one of the plurality of amplifiers, and each input impedance network providing a predetermined input impedance within the frequency band for the corresponding amplifier, wherein at least a portion of each of the plurality of input impedance networks also forms part of the monolithic integrated circuit; a plurality of output impedance networks, each output impedance network being coupled to the output of a corresponding one of the plurality of amplifiers, and each output impedance network providing a predetermined output impedance within the frequency band for the corresponding amplifier; and a control circuit coupled to each of the plurality of amplifiers for selectively enabling one of the amplifiers and disabling the remaining amplifiers in response to at least one control signal. ### Claim 13 (depends on 12) The multi-band amplifier circuit of claim 12 wherein each of the plurality of input impedance networks also forms part of the monolithic integrated circuit. ### Claim 14 (depends on 13) The multi-band amplifier circuit of claim 13 wherein each of the plurality of output impedance networks also forms part of the monolithic integrated circuit. ### Claim 15 (depends on 14) The multi-band amplifier circuit of claim 14 wherein the control circuit also forms part of the monolithic integrated circuit. ### Claim 16 (depends on 12) The multi-band amplifier circuit of claim 12 wherein each predetermined input impedance approximately matches a source impedance for an input signal of the corresponding amplifier. ### Claim 17 A multi-band amplifier circuit comprising: a plurality of GaAs amplifiers, each GaAs amplifier comprising at least one amplifying stage having at least one GaAs transistor, being configurable to receive an input'signal within a particular frequency band, and forming part of a GaAs monolithic integrated circuit; a plurality of impedance matching networks, each impedance matching network being coupled to a corresponding one of the plurality of amplifiers, and each impedance matching network providing a predetermined impedance within the frequency band for the corresponding amplifier, wherein at least a portion of each of the plurality of impedance matching networks also forms part of the GaAs monolithic integrated circuit; and a control circuit coupled to each of the plurality of amplifiers for selectively enabling one of the amplifiers and disabling the remaining amplifiers in response to at least one control signal. ### Claim 18 (depends on 17) The multi-band amplifier circuit of claim 17 wherein each of the plurality of impedance matching networks also forms part of the GaAs monolithic integrated circuit. ### Claim 19 (depends on 17) The multi-band amplifier circuit of claim 17 wherein the control circuit also forms part of the GaAs monolithic integrated circuit. ### Claim 20 (depends on 17) The multi-band amplifier circuit of claim 17 wherein each impedance matching network is coupled to an input of the corresponding GaAs amplifier to provide a predetermined input impedance within the frequency band for the corresponding GaAs amplifier. ### Claim 21 (depends on 20) The multi-band amplifier circuit of claim 20 wherein each predetermined input impedance approximately matches a source impedance for the input signal of the corresponding GaAs amplifier. ### Claim 22 (depends on 17) The multi-band amplifier circuit of claim 17 wherein each impedance matching network is coupled to an output of the corresponding GaAs amplifier and provides a predetermined output impedance within the frequency band for the corresponding GaAs amplifier. ### Claim 23 (depends on 17) The multi-band amplifier circuit of claim 17 wherein each GaAs amplifier comprises a plurality of amplifying stages arranged as a cascade, and wherein each GaAs amplifier further comprises at least one interstage impedance matching network coupled between two successive amplifying stages, each interstage impedance matching network providing a predetermined interstage impedance within the frequency band for the corresponding GaAs amplifier. ### Claim 24 (depends on 23) The multi-band amplifier circuit of claim 23 wherein the interstage impedance is such that an output impedance of one of the successive amplifying stages approximately matches an input impedance of the other of the successive amplifying stages within the frequency band for the corresponding GaAs amplifier. ### Claim 25 (depends on 17) The multi-band amplifier circuit of claim 17 wherein the frequency band for one amplifier is at near 800 MHz and the frequency band for another amplifier is near 1900 MHz. ### Claim 26 (depends on 17) The multi-band amplifier circuit of claim 17 wherein, when enabling one of the GaAs amplifiers, the control circuit further provides a predetermined bias to bias the enabled GaAs amplifier in a desired mode of operation. ### Claim 27 (depends on 26) The multi-band amplifier circuit of claim 26 herein the desired mode of amplifier operation is one of: class A, B, AB, or C operation. ### Claim 28 (depends on 17) The multi-band amplifier circuit of claim 17 wherein, in each amplifying stage of each GaAs amplifier, each GaAs transistor is a GaAs field effect transistor. ### Claim 29 A wireless communication device including a dual-band amplifier circuit, the dual-band amplifier circuit comprising: a first amplifier comprising at least one amplifying stage, being configurable to receive an input signal within a first wireless communication frequency band, and forming part of a monolithic integrated circuit within the device; a first input impedance matching network coupled to the first amplifier, the first impedance matching network being configured to provide a predetermined impedance within the first frequency band; a second amplifier comprising at least one amplifying stage, being configurable to receive an input signal within a second wireless communication frequency band, and forming part of the monolithic integrated circuit; a second input impedance matching network coupled to the second amplifier, the second impedance matching network providing a predetermined impedance within the second frequency band, wherein the first and second impedance matching networks also form part of the monolithic integrated circuit; and a control circuit coupled to each of the plurality of amplifiers for selectively enabling one amplifier and disabling the other amplifier in response to at least one control signal. ### Claim 30 An amplifier circuit comprising: an amplifier having at least one amplifying stage, the amplifier receiving an input signal in one of a plurality of frequency bands; a plurality of impedance matching networks each comprising at least one component, each impedance matching network corresponding to one of the plurality of frequency bands and providing a predetermined impedance within the corresponding frequency band, wherein the plurality of impedance matching networks includes a first impedance matching network and a second impedance matching network, and the first and second networks each include a common passive component, and wherein furthermore the first impedance matching network comprises a first passive component and a second passive component, the second impedance matching network comprises the first passive component, and the second passive component is bypassed by the switch when the switch couples the second impedance matching network to the amplifier; and a switch for selectively coupling a particular one of the plurality of impedance matching networks to the amplifier in response to at least one control signal. ### Claim 31 (depends on 30) The amplifier circuit of claim 30 wherein none of the plurality of impedance matching networks include a passive component in common with the other networks. ### Claim 32 (depends on 30) The amplifier circuit of claim 30 wherein each impedance matching network is selectively coupled to an input of the amplifier to provide a predetermined input impedance for the amplifier within the corresponding frequency band. ### Claim 33 (depends on 32) The amplifier circuit of claim 32 wherein each predetermined input impedance approximately matches a source impedance for the input signal of the amplifier when the input signal is in the corresponding frequency band. ### Claim 34 (depends on 30) The amplifier circuit of claim 30 wherein each impedance matching network is selectively coupled to an output of the amplifier to provide a predetermined output impedance for the amplifier within the corresponding frequency band. ### Claim 35 (depends on 30) The amplifier circuit of claim 30 each impedance matching network is selectively coupled to a power input of the amplifier to provide a predetermined output impedance for the amplifier within the corresponding frequency band. ### Claim 36 (depends on 30) The amplifier circuit of claim 30 wherein one frequency band is near 800 MHz and another frequency band is near 1900 MHz. ### Claim 37 (depends on 30) The amplifier circuit of claim 30 further comprising a bias control circuit for providing, in response to the frequency band of the input signal, a desired bias to the amplifier to bias the amplifier in a desired mode of amplifier operation. ### Claim 38 (depends on 37) The amplifier circuit of claim 37 wherein the desired mode of amplifier operation is one of: class A, B, AB, or C operation. ### Claim 39 (depends on 30) The amplifier circuit of claim 30 wherein each impedance matching network comprises at least one reactive component.