Delay device and method of emulating radar signal propagation delays

A delay device comprising:

• a tuning network configured to receive a reference signal at a reference frequency (fREF) and configured to produce a radio frequency (RF) output signal in an RF band, the tuning network including:
• a first tuning component including a first delay line, the first tuning component having a first frequency response, and
• a second tuning component including a second delay line, the second tuning component having a second frequency response;
• the first and second frequency responses of the first and second tuning components overlapping in an intermediate frequency (IF) band to provide a group delay response for the tuning network;
• and
• a delay modifier in communication with the tuning network and configured to provide an offset frequency as an input to the tuning network and to electronically adjust a group delay value associated with the group delay response by varying the offset frequency, the delay modifier configured to provide a local oscillator frequency,
• the difference between the reference frequency (fREF) and the local oscillator frequency being substantially equal to an intermediate frequency of the tuning network, and
• the tuning network and the delay modifier cooperating to transpose the reference signal at the reference frequency down to the IF band before passing through the first and second delay lines, and back up to the RF band after passing through the first and second delay lines.

A method of emulating radar signal propagation delays between a RADAR and a target in a RADAR system under test, comprising:

• receiving, at a tuning network including first and second tuning components having first and second delay lines, respectively, a reference signal at a reference frequency (fREF) in a RADAR frequency band;
• transposing, at the tuning network, the reference signal at the reference frequency down to an intermediate frequency band before passing through the first and second delay lines, and back up to the RADAR frequency band after passing through the first and second delay lines, an output of the first tuning component being provided as an input to the second tuning component, the first and second tuning components having first and second frequency responses, respectively, which overlap in the intermediate frequency band to provide a group delay response for the tuning network;
• providing an offset frequency as an additional input to the tuning network;
• electronically adjusting a group delay value associated with the group delay response by varying the offset frequency;
• and
• producing a radio frequency (RF) output signal, the RF output signal being in the RADAR frequency band.

A method of improving sensitivity of a communication signal transmission system configured to detect a target, comprising:

• obtaining a local oscillator signal;
• delaying the local oscillator signal by a time duration equal to a pulse round trip flight of interest between the system and the target within a distance range;
• and
• providing the delayed local oscillator signal to a receiver down converter mixer so as to cancel oscillator phase noise for a range of interest, resulting in an improvement in the clutter to signal ratio of the system.