Wideband signal generators, measurement devices, methods of signal generation, and methods of signal analysis

1. A signal generator comprising:

a clock generator comprising a first direct digital synthesizer (DDS) configured to produce a clock signal based on a clock source signal, and

a clock divider in communication with the clock generator, the clock divider comprising a second DDS, wherein the clock divider is configured to produce a divided signal based on (1) the clock signal and (2) a control signal indicating a divide ratio; and

a plurality of selectable filters in communication with the clock divider, the plurality of selectable filters being configured to produce a filtered signal based on the divided signal,

wherein a selection among the plurality of selectable filters is based on the divide ratio.

2. The signal generator according to claim 1 , wherein the clock generator includes a frequency translator in communication with the clock divider and configured to produce a translated signal based on the clock signal.

3. The signal generator according to claim 2 , wherein the frequency translator includes a mixer.

4. The signal generator according to claim 2 , wherein the frequency translator includes a mixer having a local oscillator input, and wherein the mixer is configured to receive at the local oscillator input a signal based on the clock source signal.

5. The signal generator according to claim 1 , further comprising a frequency translator in communication with at least one of the plurality of selectable filters and configured to produce a translated signal based on the filtered signal.

6. The signal generator according to claim 1 , wherein the divide ratio is at least two and less than three.

7. The signal generator according to claim 1 , in which the selection among the plurality of selectable filters is based on a user-selected frequency.

8. The signal generator according to claim 1 , in which the plurality of selectable filters includes a 1/N-octave-band filter bank, where N is an integer greater than zero.

9. The signal generator according to claim 1 , in which at least two among the plurality of selectable filters have different bandwidths.

10. A signal generator comprising:

a clock generator comprising a first direct digital synthesizer (DDS) configured to produce a clock signal based on a clock source signal;

a clock divider in communication with the clock generator, the clock divider comprising a second DDS configured to produce a divided signal based on (1) the clock signal and (2) a control signal indicating a divide ratio, and a third DDS configured to produce a second divided signal based on (1) the clock signal and (2) a second control signal indicating a second divide ratio; and

a plurality of selectable filters in communication with the clock divider, the plurality of selectable filters being configured to produce a filtered signal based on the divided signal,

wherein a selection among the plurality of selectable filters is based on the divide ratio.

11. A signal generator comprising:

a clock generator comprising a first direct digital synthesizer (DDS) configured to produce a clock signal based on a clock source signal;

a clock divider in communication with the clock generator, the clock divider comprising a second DDS, wherein the clock divider is configured to produce a divided signal based on (1) the clock signal and (2) a control signal indicating a divide ratio;

a second clock divider in communication with the clock divider, the second clock divider comprising a third DDS, wherein the second clock divider is configured to produce a divided signal based on (1) the filtered signal and (2) a second control signal indicating a second divide ratio; and

a plurality of selectable filters in communication with the clock divider, the plurality of selectable filters being configured to produce a filtered signal based on the divided signal,

wherein a selection among the plurality of selectable filters is based on the divide ratio.

12. A signal generator comprising:

a tunable clock generator configured to produce a clock signal, and

a clock divider in communication with the tunable clock generator, the clock divider comprising a direct digital synthesizer, wherein the clock divider is configured to produce a divided signal based on (1) the clock signal and (2) a control signal indicating a divide ratio; and

a plurality of selectable filters in communication with the clock divider, the plurality of selectable filters being configured to produce a filtered signal based on the divided signal,

wherein a selection among the plurality of selectable filters is based on the divide ratio.

13. A signal generator comprising:

a tunable clock generator configured to produce a clock signal;

a clock divider in communication with the tunable clock generator, the clock divider comprising a direct digital synthesizer, wherein the clock divider is configured to produce a divided signal based on (1) the clock signal and (2) a control signal indicating a divide ratio;

a second clock divider in communication with the tunable clock generator and configured to produce a second divided signal based on the clock signal, wherein the second clock divider comprises a direct digital synthesizer and is configured to produce the second divided signal based on a second control signal indicating a second divide ratio; and

a plurality of selectable filters in communication with the clock divider, the plurality of selectable filters being configured to produce a filtered signal based on the divided signal,

wherein a selection among the plurality of selectable filters is based on the divide ratio.

14. The signal generator according to claim 13 , wherein the plurality of selectable filters is in communication with the second clock divider.

15. The signal generator according to claim 13 , further comprising a switch in communication with the clock divider and the second divider and configured to select one among the divided and second divided signals.

16. The signal generator according to claim 13 , wherein at least one among the clock divider and the second clock divider includes a frequency translator.

17. The signal generator according to claim 16 , wherein at least one frequency translator is a mixer.

18. The signal generator according to claim 13 , wherein the tunable clock generator includes a direct digital synthesizer.

19. The signal generator according to claim 13 , wherein at least one direct digital synthesizer is preconfigured to output the respective divided signal at a defined frequency in response to receiving the clock source signal.

20. A method of signal generation, said method comprising:

receiving a request indicating a frequency;

determining a divide ratio based on the indicated frequency and a frequency of a clock source signal;

generating a control signal corresponding to the divide ratio;

based on the divide ratio, selecting a bandpass filter from a set of filters;

based on the control signal, producing an output signal having a principal component at the indicated frequency; and

filtering the output signal with the selected bandpass filter to pass the principal component.

21. The method of signal generation according to claim 20 , wherein producing an output signal includes providing the control word and a signal based on the clock source signal to a direct digital synthesizer (DDS).

22. The method of signal generation according to claim 20 , wherein producing an output signal includes dividing a signal based on the clock source signal by a ratio of at least two but less than three.

23. The method of signal generation according to claim 20 , wherein producing an output signal includes dividing a signal based on the clock source signal by a ratio of two-and-one-half.

24. A method of generating a signal, said method comprising:

using a direct digital synthesizer (DDS) to generate an output signal having a desired frequency component and a spurious frequency component;

monitoring a strength of the spurious frequency component; and

changing a phase offset value of the DDS based on a result of said monitoring.