Search

Active phased array antenna structure is used for modern multi-function radars. To search targets in high clutter environment, the radar receiver needs high dynamic range performance. Though active phased array antenna structure lead to increase of SNR, the SFDR is not increased. In this paper, high SFDR receiver of X-band active phased array radar was designed and manufactured. One channel digital receiver is connected to 32 T/R modules and one PCB assembly is composed to 2 channel digital receivers with RF part, ADC part, LO distribution part and digital down conversion part. A commercial FIFO board was used for digital receiver measurement about major performance in digital output signal condition. The measured digital receiver gain and SFDR is 33 dB and more than 81 dBc each.

The emergence of the internet of everything (IoE) demands high-performance, real-time multi-media and wideband networking in battery-operated mobile systems. For this reason, higher bandwidth and lower power mobile DRAMs are becoming increasingly critical. As promising candidates of next-generation mobile DRAM, the development of LPDDR4 [1] and wide-IO2 (WIO2) DRAM is ongoing these days. The conventional single data rate (SDR) wide IO DRAM [2] has achieved ×4 data bandwidth compared to LPDDR2 by increasing the number of IOs (e.g. 512 DQs). The WIO2 DRAM in this paper has 512 DQs, which is the same as SDR wide-IO DRAM, but by using double data rate (DDR) and operating at 1066Mb/s, its bandwidth achieves 68.2GB/s, which is quadrupled compared to LPDDR4 (single-die comparison). Moreover, since WIO2 DRAM is stacked in a 3D structure with the DRAM controller (system-in-package type), the input/output capacitance (CIO) is decreased and a power efficiency of 28mW/GB/s in READ operation mode is achieved.

This paper describes the new techniques to estimate the phase noise requirements of STALO for a Doppler radar application. The power spectral density of frequency modulation is derived from the phase noise characteristics of oscillator to be applied in Doppler radar systems and then the Doppler aperture function is calculated according to a signal transit time and half-power bandwidth of Doppler filter. Finally, sideband noise level of this IF signal spectrum is compared with system conditions.

This article introduces a low-cost phase detection radar aimed at measuring the human heartbeat and respiration signals without any physical connections to the human body. A continuous-wave radar targeting the chest will detect the phase difference, resulted by the time-varying target position of the heartbeat, between the transmitted signal and the reflected signal. We have tested the developed radar to measure the heartbeat and respiration signals at a distance of about 40 cm from the chest.