A 76-GHz Gunn voltage-controlled oscillator (VCO) with a high output power and a wide tuning-frequency range was fabricated by optimizing VCO circuits and using laser micromachining. The tuning-frequency range of the fabricated Gunn VCO was more than two times higher than that attained in our previous experiments by optimizing VCO circuits. The VCO attained a tuning-frequency range of 493 MHz, output power variation of 1.0 dB, and tuning-frequency linearity of 6.1% over a tuning-voltage range from 0 to 10 V. Its power consumption was 2.0 W at operation voltage of 3.6 V. And it measured output power was 13.3 dBm with DC-RF conversion efficiency of 1.0% at 76.5 GHz. Moreover, under fundamental-mode operation, it achieved low phase noise of -107.8 dBc/Hz at an offset frequency of 1 MHz. Since laser micromachining was used in fabricating the Gunn VCO, the reproducibility of its RF performance was improved.

An HEMT CCD (charge-coupled-device) matched filter for spread-spectrum communication was developed. For higher data rates, it was fabricated using a two-phase CCD based on HEMT technology. It operates at 1.6 GHz, and its calculated data rate is 100 Mbps with a PN data length of 16 bits (PN data rate is 1.6 GHz). And it attains a charge transfer efficiency (CTE) of 0.975 at 2 GHz. The HEMT CCD matched filter dissipates 173 mW from a 10-Vp-p supply, and its chip size is 0.961.03 mm. It will thus be useful for optical communication and other high-data-rate applications utilizing spread-spectrum (SS) communication.

Many different edge detectors have been proposed. Most of them output the edge intensity and the edge orientation as edge features. In this paper we state necessity of a measure which can discriminate a clear edge with small edge height from a noisy edge with large edge height. To find such a measure as an edge feature, we analyze variances within a window around the edge and propose an edge-feature extractor based on this analysis. Then it is noticed that the traditional edge intensity can be considered as two elements: edge height and edge reliability. In multiple edge cases, the condition is clarified for calculating accurate edge locations by analyzing the edge-height function. From this analysis we suggest a method for determining edge points by thresholding edge height. Our detector is compared to Canny's detector both in synthetic models and in a real image and it is demonstrated that our method produces better results in edge locations than Canny's. We also show that our method can detect edges with low edge height and high edge reliability.