Abstract: A method of determining imbalance in a vector signal modulator. First and second channels of a vector signal modulator are stimulated with a multi-tone signal having a power versus frequency spectrum having numerous of frequencies. In response to the stimulation, an output of the vector signal modulator is measured. The first and second channels are simultaneously stimulated with a multi-tone signal having essentially the same characteristics as the one used when separately stimulating the channels. Data collected from both the separate and simultaneous stimulations are used to calculate imbalance versus frequency of the vector signal modulator. Alternatively, two channels of a vector signal modulator are simultaneously stimulated with first and second multi-tone signals. The first and second multi-tone signals have tones at main frequencies and at first and second offsets thereto, respectively. Output measurements are then made and imbalances are calculated.

Abstract: A method of determining imbalance in a vector signal modulator. First and second channels of a vector signal modulator are stimulated with a multi-tone signal having a power versus frequency spectrum having numerous of frequencies. In response to the stimulation, an output of the vector signal modulator is measured. The first and second channels are simultaneously stimulated with a multi-tone signal having essentially the same characteristics as the one used when separately stimulating the channels. Data collected from both the separate and simultaneous stimulations are used to calculate imbalance versus frequency of the vector signal modulator. Alternatively, two channels of a vector signal modulator are simultaneously stimulated with first and second multi-tone signals. The first and second multi-tone signals have tones at main frequencies and at first and second offsets thereto, respectively. Output measurements are then made and imbalances are calculated.

Abstract: By combining four hexagonal ferrite spheres under the same electromagnet structure, a magnetically tuneable bandpass filter can be built in waveguide yielding high off resonance isolation, while keeping insertion loss to a reasonable value. Implementations of this filter in A, Q, U, and V bands have typical off resonance isolation greater than 70 dB and insertion loss less than 13 dB for full-band tuning. The filter can be utilized as a preselector for swept-frequency signal analyzers, for example.