E Band Based On Siw Hybrid Integrated Vco Research

Millimeter-wave frequency source is the heart of millimeter-wave radar and communication systems. Millimeter-wave voltage-controlled oscillator (VCO) is the key component of a millimeter-wave frequency source in that its output power, phase noise and turning determine the performance of the entire system. Therefore, it is important and necessary to study high-performance millimeter-wave oscillator.A new E-band millimeter-wave hybrid integrated VCO is designed in this thesis. The Millimeter-wave resonator is designed using novel guided wave structure based on substrate integrated waveguides (SIW). The varactor diode in parallel with tuning structure is used in order to implement electric tuning. The theory of millimeter-wave oscillator is introduced firstly in this thesis. The theory and functions of millimeter-wave VCO are also given. And then, the structure and characteristics of SIW are analyzed and a Ka-band SIW resonator is designed. A millimeter-wave hybrid integrated VCO is proposed, which consists of a resonant circuit based on SIW resonant, and an electric tuning in parallel with varactor diode. A novel microstrip directional coupler is proposed in order to transfer partial fundamental signal power to varactor diode. Microstrip to waveguide transmission structure is utilized at the VCO output port to reject the fundamental signal and transmit the second harmonic signal. The reflected fundament signal is transmitted to resonant circuit and used again to improve output power. In a word, the millimeter-wave hybrid integrated VCO is completed, which can produce the second harmonic signal in E-band.The measured results show that the circuit can put out the fundament signal and the second harmonic signal. The output power of the fundament signal is-30dBm at37.5GHz. The output power of the second harmonic signal is0.5mW at75.0GHz and the phase noise is about-81dBc/Hz@1MHz. The output powers of the fundament signal and the second harmonic signal are low. The varactor diode does not implement electric tuning effectively. Further study should be carried out.