Frequency generator
A frequency generator is specified which includes a pulse generator with a downstream signal conditioning circuit. The pulse generator is designed for recurring emission of pulses. The signal conditioning circuit derives a signal at a desired frequency from higher harmonic frequency components of the electrical pulses. The circuit makes it possible to produce a radio-frequency signal from a low-frequency clock signal, with little complexity and a small chip area. This is suitable, for example, for mixing with a further signal frequency onto a carrier frequency or an intermediate frequency in transceivers.
1 . A frequency generator, comprising:
a pulse generator configured to emit recurring electrical pulses at an output thereof; and
a signal conditioning circuit comprising an input coupled to the output of the pulse generator, and configured to emit a signal at a frequency which is derived from higher harmonic frequency components of the electrical pulses,
wherein the pulse generator comprises a phase detector.
2 . The frequency generator of claim 1 , wherein the pulse generator comprises a control input, and wherein the pulse generator is configured to emit the pulses as a discrete-value signal with a programmable pulse width as a function of a signal applied to the control input.
3 . The frequency generator of claim 1 , further comprising a clock generator configured to produce a periodic clock signal and couple the periodic clock signal to one input of the pulse generator.
4 . The frequency generator of claim 1 , wherein the signal conditioning circuit comprises a signal filtering circuit.
5 . The frequency generator of claim 1 , wherein the signal conditioning circuit comprises a signal amplification circuit.
6 . The frequency generator of claim 1 , wherein the phase detector has two inputs configured to receive two input signals having a matching phase angle.
7 . The frequency generator of claim 6 , further comprising a clock generator configured to produce a periodic clock signal and couple the periodic clock signal to one input of the pulse generator, wherein both inputs of the phase detector are connected to the clock generator.
8 . The frequency generator of claim 1 , wherein the phase detector comprises a programming input configured to receive a programming signal, and configured to program the duty ratio of the signal at the output of the phase detector based thereon.
9 . A frequency generator, comprising:
a pulse generator configured to generate a plurality of signal pulses at an output thereof; and
a signal conditioning circuit configured to receive the plurality of signal pulses and generate an output signal comprising a frequency that is a function of harmonic frequency components associated with the pulses.
10 . The frequency generator of claim 9 , wherein the signal conditioning circuit comprises a transformation component configured to generate a frequency spectrum response associated with the pulses.
11 . The frequency generator of claim 10 , wherein the signal conditioning circuit further comprises a filter configured to remove undesired harmonic frequency components of the frequency spectrum response.
12 . The frequency generator of claim 9 , wherein the pulse generator further comprises a programming input configured to receive a programming signal, wherein a duty cycle of the plurality of pulses is a function of the programming signal.
13 . The frequency generator of claim 12 , wherein the programming signal comprises a multi-bit digital word.
14 . The frequency generator of claim 9 , wherein the pulse generator comprises a phase detector circuit comprising first and second inputs, and configured to generate the pulses as a function of a phase angle between signals at the first and second inputs, a frequency difference between signals at the first and second inputs, or both.
15 . The frequency generator of claim 14 , further comprising a clock generator circuit configured to generate a clock signal connected to the first and second inputs of the phase detector.