| 摘要 |
An apparatus includes a stable local oscillator (202), which includes a first control loop. The first control loop includes a first voltage-controlled oscillator (206) configured to generate a first output signal (214) and a first phase-locked loop (208). The apparatus also includes a frequency up-converter (224) configured to increase a frequency of the first output signal. The apparatus further includes a second control loop (204) configured to receive the up-converted first output signal. The second control loop includes a second voltage-controlled oscillator (236) configured to generate a second output signal (246) and a second phase-locked loop (238). The second control loop may further include a mixer (230) having a first input coupled to the frequency up-converter, a second input coupled to the second voltage-controlled oscillator, and an output coupled to the second phase-locked loop. A reference frequency source (252) may be configured to generate a signal identifying a reference frequency and to provide that signal to the phase-locked loops. |
