In conventional near electromagnetic field measurements, there is a problem where a primary noise source cannot be separately identified from candidates of noise sources operating at the same frequency. Therefore, we propose a method to identify the offending wiring by comparing the change in the radiated noise using a notch filter subject to a differential pair pattern. In the experiment, the effectiveness was confirmed for even-order harmonic wave noise, but it was not effective for odd low-order harmonic wave noise. This report examines the reason for the ineffectiveness and demonstrates additional experiments.
Experimental results show that implementing common-mode countermeasures in printed wiring is important in order to identify odd low-order harmonic wave noise using the proposed method.
This paper first discusses a design for a compact resonator using a Composite Right/Left-Handed Transmission Line (CRLH-TL). Moreover, an All-resonator type diplexer using proposed resonators is designed and fabricated. The measured frequency characteristics for the fabricated diplexer are mostly in agreement with an electromagnetic (EM) simulated one. The size of the measured diplexer is 6.3 mm × 4.35 mm (0.068λg × 0.047λg), which is much smaller than other compact diplexers.