This paper presents principles of a down-converted mixer for four sub-harmonic designed by ADS software. The LO and RF frequencies are 23GHz, 92-94GHz respectively. The structure of ridge waveguide to microstrip transitions is optimized by CST simulation software, and W-band signals are directed to mixer RF side. The simulation results show that this mixer achieves higher 1 dB compression point, loss of frequency conversion less than 15 dB and good linearity.

Innovation of computing technology is either to improve the security and performance, or to improve  the convenience of user operation of system, networking and device, but sometimes it’s hard to get a very good balance between the two, in particular, the traditional localized OS and computing devices are inherently incompatible  in some respects with today's network environment,  therefore, although many innovations help to improve the safety, autonomy and controllability of system and device, but they are still always lacking the trustworthiness of users, one of the reasons is that their performance is lower than  user's expectation, but their operation become more complicated than before. The semi-network operating system is designed according to user's actual experience, which not only utilizes the shared attributes of network to increase the flexibility of OS, but also utilizes the stability and user-autonomy attributes of local platform ensure the base functions of OS, in addition, it can greatly reduce the burden on user’s operation and maintenance of computing system, so which will be a trustworthy system architecture for users.

This paper introduces the basic structure of narrow-band FIR filter and conducts detailed analysis on the various components of narrow-band FIR filter. Based on the CIC and HBF, this paper further designs narrow-band FIR filter with the sampling rate of 100 KHz. The materials of filter adopt the piezoelectric ceramic vibrator with high mechanical quality factorand high stability .Moreover, the simulation results indicate that this filter can greatly reduce the calculation amount and storage capacity so as to satisfy the real-time processing requirements of the signals.

Intermittent intensity clutter in wind profiling radar severely interferes with the identification and spectrum estimation of atmospheric echo signals. In order to remove such clutter, a method based on Fractional Fourier transform (FrFT) is presented. The proposed method makes use of energy concentration property of intermittent clutter in fractional Fourier frequency domain. Not only the intermittent intensity clutter can be removed in the fractional Fourier frequency domain by using a narrow band-stop filter, but also the atmospheric signal in the time domain can be reconstructed after removing the clutter. Computer simulations have verified the effectiveness of the method.

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