# US 2014/0378079 A1 · Dual mode radio frequency receivers for wideband signal processing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0378079 A1 - Document ID: US20140378079A1 - Status: Published application - Kind: A1 - Application number: 14/305,308 - Filed: 2014-06-16 - Published: 2014-12-25 - Earliest claimed: 2013-06-21 - Assignees: ThinkRF Corporation - Applicants: ThinkRF Corporation - Inventors: Nikhil Adnani; Tim Hember; Gilbert Brunette - Web page: https://patentgrep.com/patent/US20140378079A1 ## CPC - H04B 1/16: Circuits - H04B 1/406: {with more than one transmission mode, e.g. analog and digital modes} - H04B: TRANSMISSION ## Abstract Wireless communication is ubiquitous today with increasing deployments leading to increased interference, increasing conflicts, etc. Monitoring the wireless environment is therefore important for regulators, service providers, Government agencies, enterprises etc. Such monitoring should be flexible both in networks monitored within the wireless environment as well as detecting unauthorized transmitters, allowing dynamic network management, etc. However, such real time spectral/signal analysis in the prior art requires both a wideband direct conversion receiver (DCR), for high performance, wideband, fast, programmable spectral analysis, and a super heterodyne receiver for fast, narrowband, programmable demodulation for signal analysis. According to embodiments of the invention a single receiver design methodology exploiting a single RF circuit to provide superheterodyne and direct conversion receiver functionalities. ## Claims ### Claim 1 A device comprising: a first filter characterised by a first frequency characteristic; a second filter characterised by a second frequency characteristic; an RF processing circuit for receiving RF signals within a frequency range compatible with the first and second frequency characteristics and processing said received RF signals to generate a processed RF output signal; a programmable quadrature demodulator block coupled to the RF processing circuit comprising a first mixer receiving a local oscillator signal, a second mixer receiving the local oscillator signal with a predetermined phase offset, the programmable quadrature demodulator block operating in a first mode and a second mode wherein the first mode comprises coupling the processed RF output signal to both first and second mixers and generating first and second outputs representing in-phase and quadrature components of the processed RF output signal; and the second mode comprises coupling the processed RF output signal to only the first mixer, generating a down converted signal in dependence upon the processed RF signal and the local oscillator signal, and selectively blocking output from the second mixer. ### Claim 2 (depends on 1) The device according to claim 1 wherein, the first filter is at least one of a low pass filter, high pass filter, and a bandpass, the at least one of selected in dependence upon a range of RF frequencies to be rejected by the first filter; the second filter is at least one of a band pass filter, a low pass filter and a high pass filter. ### Claim 3 (depends on 1) The device according to claim 1 wherein, at least of the first frequency characteristic and the second frequency characteristic are established in dependence upon a predetermined frequency range, said predetermined frequency range defining the frequency range compatible with the first and second frequency characteristics. ### Claim 4 (depends on 1) The device according to claim 1 wherein, at least of the first frequency characteristic and the second frequency characteristic are established in dependence upon a predetermined frequency range, wherein the at least one of results in at least one of: rejecting RF signals with frequencies that would result in undesired signals at the output of the programmable quadrature demodulator block when operating in the first mode; and rejecting RF signals with at least one of frequencies and image frequencies that would result in undesired signals at the output of the programmable quadrature demodulator block when operating in the second mode. ### Claim 5 (depends on 4) The device according to claim 4 wherein, the first filter is a SAW filter bank comprising at least two SAW filters of a plurality of SAW filters, the first filter allowing the frequency range of the processed RF output signal to be switched between at least a first intermediate frequency range and a second intermediate frequency range such that an undesired signal maybe removed by changing the undesired signal to one of a sum and a difference between the received RF signals and a local oscillator signal within the RF processing circuit. ### Claim 6 (depends on 1) The device according to claim 1 wherein, the first filter is a SAW filter and the second filter is an anti-aliasing filter such that the device may reject out of band signals at baseband whilst maximizing processed RF signal bandwidth. ### Claim 7 (depends on 6) The device according to claim 6 wherein, the programmable quadrature demodulator block when operating in the second mode may be reconfigured to replace a low pass filter within the programmable quadrature demodulator block with a band pass filter. ### Claim 8 (depends on 1) The device according to claim 1 wherein, the first filter is a filter exploiting at least one of passive electrical elements and active electrical elements; and the second filter is a SAW filter. ### Claim 9 (depends on 1) The device according to claim 1, wherein the output from the device passes through three filters including the first filter and the second filter such that no direct path from the input of RF processing circuit to the output of the programmable quadrature demodulator block exists. ### Claim 10 (depends on 9) The device according to claim 9, wherein the three filters each respectively form part of a front-end pre-select filter bank, a SAW filter bank, and an anti-aliasing filter bank. ### Claim 11 (depends on 1) The device according to claim 1 further comprising; a plurality of first filters of which the first filter is one and the first frequency characteristic is the 3 dB cut-off frequency of the first filter; a plurality of second filters of which the second filter is one and the second frequency characteristic is the 3 dB cut-off frequency of the second filter; and a switching circuit to selectively couple the received RF signal to a predetermined first filter of the plurality of first filters, to couple the output of the first filter of the plurality of first filters to the RF processing circuit, to couple the output of the RF processing circuit to a predetermined second filter of the plurality of second filters, and from the predetermined second filter of the plurality of second filters to the programmable quadrature demodulator block. ### Claim 12 A method comprising; processing a received RF signal using an electronic circuit to generate an output signal, the output signal being generated in dependence of a homodyne process when the electronic circuit is configured in a first mode and in dependence of a heterodyne process when the electronic circuit is configured in a second mode. ### Claim 13 (depends on 12) The method according to claim 12 wherein, re-configuring the electronic circuit from the second mode to the first mode comprises the steps of selecting the appropriate front-end filter, establishing a local oscillator at a first frequency and decoupling a first mixer of a pair of mixers from the output of the electronic circuit, and determining whether to reconfigure a SAW filter bank to select a different SAW filter than the SAW filter employed in the second mode; and re-configuring the electronic circuit from the first mode to the second mode comprises the steps of establishing the local oscillator at a second frequency, re-coupling the first mixer of the pair of mixers to the output of the electronic circuit, and selecting an appropriate anti-aliasing filter. ### Claim 14 (depends on 12) The method according to claim 12 wherein; processing the received RF signal using an electronic circuit comprises using an electronic circuit comprising: a plurality of first filters, each first filter being at least one of a low pass filter, high pass filter, and a bandpass filter and characterized by at least a predetermined 3 dB cut-off frequency; a plurality of second filters, each second filter being a characterized by a predetermined 3 dB cut-off frequency; and a switching circuit to selectively couple the received RF signal to a predetermined first filter of the plurality of first filters and then a predetermined second filter of the plurality of second filters prior to the received RF signal is coupled to the portion of the electronic circuit comprising the pair of mixers. ### Claim 15 (depends on 12) The method according to claim 12 wherein; each first filter of the plurality of first filters is at least one of a low pass filter, high pass filter, and a bandpass filter exploiting at least one of passive electrical elements and active electrical elements; and each second filter of the plurality of second filters is a SAW filter. ### Claim 16 (depends on 14) The method according to claim 14 wherein, the electronic circuit comprises an RF processing circuit of a plurality of processing circuits, each RF processing circuit for processing received RF signals within a predetermined frequency range to generate a processed RF output signal; and the switching circuit further selectively couples the RF processing circuit of the plurality of processing circuits between the predetermined first filter of the plurality of first filters and the predetermined second filter of the plurality of second filters prior coupling the processed and filtered received RF signal to that portion of the electronic circuit comprising the pair of mixers. ### Claim 17 (depends on 14) The method according to claim 14 wherein, at least of the first frequency characteristic and the second frequency characteristic are establish a predetermined frequency range, said predetermined frequency range defining the frequency range compatible with the first and second frequency characteristics. ### Claim 18 (depends on 14) The device according to claim 14 wherein, at least of the first frequency characteristic and the second frequency characteristic are established in dependence upon a predetermined frequency range, wherein the at least one of results in at least one of: rejecting RF signals with frequencies that would result in undesired signals at the output of a programmable quadrature demodulator block when operating in the first mode; and rejecting RF signals with at least one of frequencies and image frequencies that would result in undesired at the output of a programmable quadrature demodulator block when operating in the second mode. ### Claim 19 (depends on 18) The device according to claim 18 wherein, the first filter is a SAW filter bank comprising at least two SAW filters of a plurality of SAW filters, the first filter allowing the frequency range of the processed RF output signal to be switched between at least a first intermediate frequency range and a second intermediate frequency range such that an undesired signal maybe removed by changing the undesired signal to one of a sum and a difference between the received RF signals and a local oscillator signal within the RF processing circuit. ### Claim 20 (depends on 14) The device according to claim 14 wherein, the first filter is a SAW filter and the second filter is an anti-aliasing filter such that the device may reject out of band signals at baseband whilst maximizing processed RF signal bandwidth. ### Claim 21 (depends on 20) The device according to claim 20 wherein, a programmable quadrature demodulator block comprising a predetermined portion of the electronic circuit when operating in the second mode may be reconfigured to replace a low pass filter within the programmable quadrature demodulator block with a band pass filter ### Claim 22 A device comprising a single RF receiver block supporting both superheterodyne and direct conversion receiver functionality. ### Claim 23 (depends on 22) The device according to claim 22, wherein the device comprises at least a programmable quadrature demodulator block operable in a first mode and a second mode for receiving an RF signal and generating an output signal, the programmable quadrature demodulator block comprising a first mixer receiving a local oscillator signal and a second mixer receiving the local oscillator signal; wherein in the first mode the programmable quadrature demodulator block couples the RF signal to both first and second mixers and generates first and second outputs representing in-phase and quadrature components of the processed RF output signal; and in the second mode the programmable quadrature demodulator block couples the RF signal to only the first mixer and generates a down converted output signal.