Research And Design Of Amplitude Control Circuit For Millimeter Wave Wireless Applications

The growing demand for high data rate wireless communications is accelerating the deployment of millimeter-wave(mm-wave)mobile communication networks worldwide.however,the high spatial path loss of signal propagation in the mm-wave band limits communication distances.As the key technology of millimeter wave communication,phased array can extend the transmission distance and realize spatial multiplexing through beamforming.As the key module of phased array,it is of great significance to carry out the research and design of amplitude control circuit.In this thesis,the basic theory of phased array system is briefly introduced,and the important function of amplitude control circuit is analyzed firstly.Then the basic principle,main index and common structure of the amplitude control circuit are introduced in detail,which is fully prepared for the subsequent circuit design.For the phased array radar system,the reasons for the additional phase shift of the amplitude control circuit are analyzed from the traditional passive attenuator structure,and two passive attenuators are designed based on the phase compensation principle of series capacitors and parallel capacitors.The first 5-bit attenuator is based on 130 nm Si Ge process,the operating frequency band is 33-37 GHz,the attenuation step is 0.5d B(32 states),The test results of the system version: RMS amplitude error < 0.65 d B,RMS phase amplitude error < 3°.The second 3-bit attenuator is based on 65 nm CMOS process and uses an improved layout to reduce the area,the operating frequency band is90-100 GHz,the attenuation step is 1d B(8 states).The test results of the single-test version: RMS amplitude error < 0.5d B,RMS phase error < 2°.For wireless communication systems,the reasons for the additional phase shift of the amplitude control circuit are analyzed from a simple common source amplifier,and two variable gain amplifiers with different gain adjustment ranges are designed based on the active cross-coupling phase compensation structure.At the same time,a new type of ?-type resistor network is used in the second variable gain amplifier to reduce the impedance change during the state adjustment.The two variable gain amplifiers are based on 65 nm CMOS process,the operating frequency band is 71-76 GHz,the attenuation step is 0.25/0.5d B(64 states),the simulation results: the maximum gain at the center frequency point>10/12 d B,RMS amplitude error <0.12/ 0.35 d B,RMS phase amplitude <1.3/2°,OP1 d B is 7.2/6.2d Bm,DC power consumption is 58/65 m W.