Research On 3 Millimeter Band Solid-state Power Combining Amplifying Technology

Generally,the single solid-state power amplifier in 3mm band is still at the milliwatt-level, the realization of multi-way, high efficiency and high power output power combining in this band is not only of strategic value to system application, but also one of the key problem of research in 3mm band. Taking advantage of low-loss of the metallic waveguide in 3mm band, this thesis has studied on various power combining networks about the aspects of combining-structure, bandwidth, power combining efficiency, etc. The main results are as follows.1.Based on the theory of the E-plane waveguide-microstrip probe transition, the waveguide-microstrip single probe has been designed, manufactured and measured in 3mm band. This structure has the advantages of easy installation, low-loss and easy to heat dissipation for solid-state device, thus it is appropriate for broadband and high-power application in 3mm band. In 75-103.5GHz, the reflection coefficients at ports are less than-20 dB, the insertion loss is less than 2.2dB, taking out of the transmission line loss, the insertion loss of this transition is about 0.25 dB.2.Based on the theory of waveguide T-junction, the waveguide E-plane T-junction, waveguide H-plane T-junction and magic Tee have been studied and developed in 3mm band respectively. The measured results shows that the three hybrids have good amplitude and phase consistency, port VSWR and easy manufacturing.3.Based on the theory of waveguide branch hybrid, the E-plane waveguide branch hybrid has been studied and developed in 3mm band. In 85-100 GHz, S21,S31 are about-3.2dB~-3.4dB. Same work is been done on H-plane waveguide branch hybrid, In 85-100 GHz, the reflection coefficients at each port are less than-15 dB, transmission coefficients have good amplitude consistency, within 0.32 dB,the loss of the hybrid is about 1dB.4.Based on the theory of waveguide rat-race hybrid, a general design approach of waveguide rat-race hybrid in 3mm band is summarized. Waveguide rat-race hybrid is designed, developed, and the measured results show that in 75-103 GHz, the port return loss is great than 15 dB while the transmission coefficients is about-3.3dB~-3.4dB. Taking the advantages of low-loss, wide bandwidth, high isolation and easy manufacture, the hybrid is suitable for power combining amplifying application in 3mm band.5.Based on the waveguide rat-race hybrid power combining network, a power combining amplifier has been developed. In 88-92 GHz, the max output power of the module is greater than 1.8W, the maximum value is about 3.203W@88.5GHz, in88.5-94 GHz, the power combining efficiency of this module is more than 70%, and the maximum value is about 86.4%@91GHz. Then an eight-way power combining network has been designed and manufactured and measured, the test results show that in 85-100 GHz, the measured insertion loss of the network is about 4.2-4.5dB, taking out of the transmission line loss, the insertion loss of this combining network is about 2.4-2.7dB, the corresponding power combining efficiency is about 73.3%-75.8%.