Zaytsev A. A., Kovbasa A. P., Shayda V. A.

SRI Quant-Transport Dimitrova 5, Kiev 03150, Ukraine Tel: (+380-44) 227-0798, fax (+380-44) 268-3750 E-mail: V. Shayda@ktrans.kiev. ua

Abstract Millimeter band transceiver design principles are reviewed. Transceiver is designed for millimeter waveband radar, with non-interrupting emission, phase-manipulated by Msequence. Technical characteristics of transceiver and its parts are shown. Transceiver is designed for car radar operating in 76-77 GHz waveband.

I.  Introduction

The most complicated task when designing millimeter-band transceiver with phase manipulation (like M-sequence modulation) is to develop phase modulator. Such a modulator must allow to change phase of output signal from 0 to л at 10ns or faster, with parasitic amplitude modulation not higher than 0.1 dB.

II.  The main part

Scheme of transceiver proposed allows to obtain modulated signal at lower frequencies where the problem is solved much easier. Output signal of transmitter is obtained by adding frequencies of support oscillator Fsup and that of base frequency oscillator Fbfg (this oscillator also provides phase manipulation of its output) in a mixer and its amplification up to the desired level. Besides, support oscillator is the first heterodyne of receiver. Structural scheme of transceiver is shown in Fig.1.

Base frequency oscillator 1 generates signals with a 3GHz frequency and short-term frequency stability of 10′9 made by PLL and high-stability crystal oscillator.

Phase modulator 2 allows phase binary modulation 0 to л with 10ns element duration, 2ns steepness of forward and back fronts with parasitic amplitude modulation not higher than 0.1dB.

Divider 3 performs division of a signal from output of modulator 2 in 1:10 ratio. Signal with a higher power comes to mixer

9  as a second heterodyne signal. Signal with the lower power (1 mW) comes to sounding signal generator 4.

Support oscillator 6 produces support signal at 73GHz, with

10  mW power. This signal is then divided in splitter 7 onto 2 equal parts and then it is given to the sounding signal generator

4    and receiver mixer 12.

Mixer 12 gets signal from Input 1, from receiving antenna system. From the output of mixer 12, signal with the first intermediate frequency 3GHz comes to low-noise amplifier 8 with a noise ration about 1,5dB in 1000MHz frequency band. From the output of amplifier 8, signal comes to 2" mixer 9. Mixer 9 provides synchronous detection. Signal from its output goes through amplifier 10 with 20-25dB gain onto Output 2 and than can be digitized by ADC.

Phase modulator is driven by control circuit 11, which gets modulating signals generated in radar control system at its input (Input 2 of transceiver).

Parameters of transceiver are the following:

Output sounding signal has: Frequency 76 GHz, Power 20 mW. Impulse phase modulation 0In (minimal time of phase change 2ns). Noise ratio of the receiver is < 9 dB.

III.  Conclusion

Transceiver is designed to be used in car monoimpulse radar with continuous emission and phase-code modulation with the following parameters:

distance to object up to 200m max speed of relative movement 300 kmh accuracy of speed determination 2% accuracy of distance determination 3% accuracy of angle coordinate determination ±1°.

Джерело: Матеріали Міжнародної Кримської конференції «СВЧ-техніка і телекомунікаційні технології», 2003р.