Research And Design Of Compact Multi-frequency Microstrip Antennas And Power Divider

The receiving and transmitting antenna and microwave divider play a vital role in the wireless system.Meanwhile,the microstrip antenna has many merits,such as light weight,compact structure,low profile surface,easy to process and easy to integrate the passive circuit.Many researchers focus their work on the microstrip antenna and power divider.Firstly,this paper simply introduces the development of microstrip antenna,power splitter,and introduces the multi-frequency and the miniaturization of the microstrip antenna and phase consistency of power splitters technologies.And then,the author designs two microstrip antennas with the method of slotting and branch.The first antenna size is 48 mm×47 mm×1.5 mm,which can resonant four bands: 1.495 GHz-1.66 GHz,1.75 GHz-1.945 GHz,2.355 GHz-2.7 GHz and 3.4 GHz-3.6 GHz.This antenna can cover the wireless system of Bluetooth/FDD-LTE/TD-LTE/ WLAN/WIMAX,which can be applied to phone and other mobile terminals.The branch of second antenna was added on the ground,the size of substrate is 30 mm×21 mm×1.5 mm.The author established the antenna on the basis of the first original model.Compared to the first antenna,this antenna size reduces to 28 percent of the first antenna.The antenna can resonant four bands: 2.285 GHz-2.332 GHz,3.4 GHz-3.61 GHz,4.15 GHz-4.5 GHz and 4.7 GHz-5.9 GHz.This antenna can work at the low frequency of 5 generation,which includes 4.4 GHz-4.5 GHz and 4.8 GHz-4.99 GHz,and can also cover the wireless system of TD–LTE /WIMAX/WIFI.The measurement and simulation results are in good agreement after fabrication and test,which provides a novel design method for the research of 5G.Finally,according to the project requirement,and in order to improve the antenna feed system of solid-state amplifier input signal phase consistency issues,the power divider was designed.The proposed structure consists of coaxial line,T structure stripline and radial line and the quarter-wavelength transformor.Coupling conductor is to solve the issue of phase consistency.In the working frequency band 5.3 GHz to 5.9 GHz,input return loss is less than-18.3 dB,output return loss is less than-15.3 dB,phase consistency is better than ±1degree,and insertion loss is less than 0.2 dB.