Hiroyoshi Yamada

Superresolution techniques for time-domain measurements with a network analyzer

Superresolution techniques for time delay estimation are proposed and applied to frequency-domain data measured with a network analyzer. A MUSIC (multiple signal classification) algorithm preprocessed by spatial smoothing is used. The spatial smoothing preprocessing is performed to destroy signal coherence, and the decorrelation performance is examined in detail. The expression which gives an individual response is given. Using this expression, it is possible to eliminate unwanted signals that appear as ripples in the frequency domain. Experimental results show that the frequency bandwidth required by the MUSIC algorithm to resolve distinct time-domain responses and eliminate unwanted signals is much narrower than that required by the FFT (fast Fourier transform). Thus, the MUSIC algorithm is applicable to the time-domain measurements with the network analyzer and has much higher resolution capability than the conventional FFT techniques. The MUSIC algorithm is one of the most promising methods of enhancing the accuracy of measurement for narrowband devices such as antennas. >

A time-domain superresolution technique for antenna measurements and scattering studies

The authors show that the superresolution technique can be used for antenna measurements and scattering studies. They describe experimental results of antenna measurements and simulation results of electromagnetic scattering mechanism extraction using MUSIC. It is shown that, using MUSIC, one can isolate the individual scattering centers and can obtain each diffraction coefficient using much narrower bandwidth data than the FFT (fast Fourier transform) and gating techniques.<<ETX>>

Time-domain measurements using a superresolution technique

The superresolution technique is applied to frequency-domain data measured with a network analyzer, and the high-resolution capability is shown by experimental results. A MUSIC (multiple signal classification) algorithm is used because it has several advantages. Experimental results demonstrate that the superresolution technique has a much better capability of resolving signals and analyzing parameters (e.g., the reflection coefficient) than the FFT and the gating technique. The superresolution technique is expected to be useful for time-domain measurements of narrowband devices such as antennas.<<ETX>>