# US 7,610,023 B2 · Voltage controlled oscillator band switching system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,610,023 B2 - Document ID: US7610023B2 - Status: Granted - Kind: B2 - Application number: 11/187,150 - Filed: 2005-07-22 - Published: 2007-01-25 - Granted: 2009-10-27 - Earliest claimed: 2005-07-22 - Assignees: Pine Valley Investments, Inc. - Inventors: Dale Scott Douglas - Web page: https://patentgrep.com/patent/US7610023B2 ## CPC - H04B 1/005: {adapting radio receivers, transmitters andtransceivers for operation on two or more bands, i.e. frequency ranges} - H03L 7/095: using a lock detector (H03L7/087 takes precedence) - H03L 7/10: for assuring initial synchronisation or for broadening the capture range - H04B: TRANSMISSION - H03L: AUTOMATIC CONTROL, STARTING, SYNCHRONISATION OR STABILISATION OF GENERATORS OF ELECTRONIC OSCILLATIONS OR PULSES (generation of oscillations H03B) ## Abstract An apparatus, method, and system for voltage controlled oscillator band switching are described. A band switching apparatus may include a reference generation and comparison module, a clock pulse generation module, and a counter and gating module. The reference generation and comparison module may generate a positive signal based on a comparison of a loop filter voltage associated with a voltage controlled oscillator to a maximum tuning voltage and a minimum tuning voltage. The clock pulse generation module may generate a clock pulse in response to the positive signal. The counter and gating module may disable band switching of the voltage controlled oscillator when a lock condition is detected and the loop filter voltage is between the maximum tuning voltage and the minimum tuning voltage. Other embodiments are described and claimed. ## Claims ### Claim 1 A band switching apparatus, comprising: a reference generation and comparison module to generate a positive signal based on a comparison of a loop filter voltage associated with a voltage controlled oscillator to a maximum tuning voltage and a minimum tuning voltage; a clock pulse generation module to generate a clock pulse in response to said positive signal; and a counter and gating module to disable band switching of said voltage controlled oscillator when a lock condition is detected and said loop filter voltage comprises a voltage between said maximum tuning voltage and said minimum tuning voltage. ### Claim 2 (depends on 1) The band switching of claim 1, wherein said reference generation module comprises a phase-locked loop filter to provide said loop filter voltage based on an output voltage waveform of said voltage controlled oscillator. ### Claim 3 (depends on 1) The band switching apparatus of claim 1, wherein said reference generation module comprises a first comparator to compare said loop filter voltage to a first reference voltage and a second comparator to compare said loop filter voltage to a second reference voltage. ### Claim 4 (depends on 1) The band switching apparatus of claim 1, wherein said clock pulse generation module comprises a low-pass filter and said clock pulse comprises a time constant associated with said low-pass filter. ### Claim 5 (depends on 4) The band switching apparatus of claim 4, wherein said clock pulse generation module comprises a logic gate to generate said clock pulse based on a first input comprising said positive signal and a second input comprising said positive signal delayed by said time constant. ### Claim 6 (depends on 4) The band switching apparatus of claim 4, wherein said clock pulse generation module comprises a switch to short said low-pass filter to ground. ### Claim 7 (depends on 1) The band switching apparatus of claim 1, wherein said clock pulse generation module comprises an inverter chain and said clock pulse comprises a time constant equal to a delay through said inverter chain. ### Claim 8 (depends on 7) The band switching apparatus of claim 7, wherein said clock pulse comprises a pulse width proportional to said inverter chain. ### Claim 9 (depends on 1) The band switching apparatus of claim 1, wherein said counter and gating module comprises a counter to output a band select word to said voltage controlled oscillator. ### Claim 10 (depends on 9) The band switching apparatus of claim 9, wherein said counter outputs said band select word if a lock condition is not detected. ### Claim 11 (depends on 9) The band switching apparatus of claim 9, wherein said band select word controls band switching of said voltage controlled oscillator. ### Claim 12 (depends on 1) The band switching apparatus of claim 1, wherein said counter and gating module comprises a register to disable band switching in response to a clock edge provided by a logic gate. ### Claim 13 (depends on 12) The band switching apparatus of claim 12, wherein said clock edge is delayed by an inverter chain. ### Claim 14 A band switching method, comprising: generating a positive signal based on a comparison of a loop filter voltage associated with a voltage controlled oscillator to a maximum tuning voltage and a minimum tuning voltage; generating a clock pulse in response to said positive signal; and disabling band switching of said voltage controlled oscillator when a lock condition is detected and said loop filter voltage comprises a voltage between said maximum tuning voltage and said minimum tuning voltage. ### Claim 15 (depends on 14) The band switching method of claim 14, further comprising providing said loop filter voltage based on an output voltage waveform of said voltage controlled oscillator. ### Claim 16 (depends on 14) The band switching method of claim 14, further comprising comparing said loop filter voltage to a first reference voltage and comparing said loop filter voltage to a second reference voltage. ### Claim 17 (depends on 14) The band switching method of claim 14, wherein generating said clock pulse comprises delaying said positive signal by a time constant associated with a low-pass filter. ### Claim 18 (depends on 14) The band switching method of claim 14, wherein said clock pulse comprises a time constant equal to a delay through an inverter chain. ### Claim 19 (depends on 14) The band switching method of claim 14, further comprising outputting a band select word to said voltage controlled oscillator if a lock condition is not detected. ### Claim 20 (depends on 19) The band switching method of claim 19, further comprising controlling band switching of said voltage controlled oscillator based on said band select word. ### Claim 21 (depends on 14) The band switching method of claim 14, wherein disabling band switching comprises generating a clock edge in response to a detected lock condition. ### Claim 22 (depends on 20) The band switching method of claim 20, further comprising delaying said clock edge by an inverter chain. ### Claim 23 A system, comprising: an antenna; and an integrated circuit coupled to said antenna, said integrated circuit comprising a band switching apparatus, said band switching apparatus comprising: a reference generation and comparison module to generate a positive signal based on a comparison of a loop filter voltage associated with a voltage controlled oscillator to a maximum tuning voltage and a minimum tuning voltage; a clock pulse generation module to generate a clock pulse in response to said positive signal; and a counter and gating module to disable band switching of said voltage controlled oscillator when a lock condition is detected and said loop filter voltage comprises a voltage between said maximum tuning voltage and said minimum tuning voltage. ### Claim 24 (depends on 23) The system of claim 23, wherein said integrated circuit comprises a complementary metal oxide semiconductor voltage controlled oscillator. ### Claim 25 (depends on 23) The system of claim 23, wherein said integrated circuit comprises a phase-locked loop filter to provide said loop filter voltage based on an output voltage waveform of said voltage controlled oscillator.