GHz에서 전후방비가 15 dB 이상이며, 스위칭에 따라서 8방향으로 빔 조향이 가능하다. AbstractIn this paper, a 2.6 GHz switched parasitic array(SPA) antenna is designed to resolve the device interference in the femtocell. The designed SPA antenna structure consists of a central λ/4 monopole antenna as a radiator and surrounding four parasitic elements operating as a reflector or a director depending on the switching state. In addition, open state monopoles around the parasitic elements are placed to improve the directivity. The designed antenna utilizes RF FETs as switching elements instead of conventional PIN diodes, which enables beam steering with a simple structure consuming low power. To select the proper FET switch, the performance of the SPA antenna depending on the switch characteristics is analyzed. The fabricated antenna has 65 mm radius and 35 mm height, which shows about 15 dB front-back-ratio(FBR) at 2.6 GHz and enables eight-directional beam steering.

This work presents a 77 GHz radar transmitter for the automotive radar system. An integrated 13 GHz frequency synthesizer fabricated using 130 nm RF CMOS process drives a commercial W-band compound semiconductor monolithic multifunction amplifier(MPA), which includes a frequency multiplier by six to generate 77 GHz transmitting signal. The 13 GHz frequency synthesizer includes a high efficiency injection buffer of 4 dBm output power to drive the MPA. The output power of 77 GHz radar transmitter is higher than 13.99 dBm and the magnitude of the reference spur relative to the carrier is -36.45 dBc. The phase noise is -81 dBc/Hz at 1 MHz offset frequency from the carrier.

This work presents the design and measured results of the single channel automotive radar system for 76.5～77 GHz long range FMCW radar applications. The transmitter uses a commercial GaAs monolithic microwave integrated circuit(MMIC) and the receiver uses the down converter designed using 65 nm CMOS process. The output power of the transmitter is 10 dBm. The down converter chip can operate at low LO power as -8 dBm which is easily supplied from the transmitter output using a coupled line coupler. All MMICs are mounted on an aluminum jig which embeds the WR-10 waveguide. A microstrip to waveguide transition is designed to feed the embedded waveguide and finally high gain horn antennas. The overall size of the fabricated radar system is 80 mm×61 mm×21 mm. The radar system achieved an output power of 10 dBm, phase noise of -94 dBc/Hz at 1 MHz offset and a conversion gain of 12 dB.