(A) narrow-band short range pulse radar with a high efficient pulse oscillator

Abstract

Recently, the short range radar has been widely used in the various automotive applications. There are various design issues to satisfy the requirements for automotive applications; Minimizing the size, lowering the cost, the maximum detection range, high resolution, high accuracy, fast data up-date time, and high power-efficiency, so on. In this thesis, pulse oscillator and mixer for the short range radar are proposed and the short range radar using long pulse is proposed. In the short pulse radar, the short pulse generation is key component. The previously reported pulse generators are inefficient power characteristics because the generator consume the power when it does not radiate pulse. In this thesis, the power efficient pulse oscillator is proposed. The oscillator uses common base inductive feedback topology without output buffers, and a bias current is switched on and off with pulse control voltages. The oscillator does not use the bias current when it does not work, which leads to high power efficiency. The pulse oscillator was fabricated using InGaP/GaAs HBT technology and measured. The oscillator shows very excellent performance both in the CW mode and pulse mode operations. In the CW mode, a high output power of 8 dBm, a low phase noise of -120.83 dBc/Hz, and a frequency tuning range of 2.3 GHz are measured. In the pulse mode, the oscillator shows a 1ns pulse width and 5 ps of phase jitter. The proposed oscillator was developed for automotive UWB short-range sensors and can be widely utilized for the sensor system requiring low-power operation. In the short range radar system, the direct conversion receiver is preferred for the simple structure system and lower cost. In the direct conversion receiver, LO leakage is the most important issue. In this thesis, the K-band high LO-to-RF isolation mixer is proposed. The mixer was fabricated using InGaP/GaAs HBT technology and measured by comparing the conventional double balance mixer. The LO-to-RF iso...