Design Of Broadband Lens Antennas

Broadband lens antennas are widely used for microwave shielding performance measurement, electro magnetic compatibility measurement, electromagnetic parameters measurement and so on. High gain, high efficiency, wide-band make broadband lens antennas popular in microwave testing systems. According to the needs of "microwave lens equipment", four broadband lens antennas are designed in this article. They work at2-4GHz,4-8GHz,8-18GHz and18-40GHz, separately. VSWR<2.0and gain>15dB are required.The main content of this article is listed as follows:1.The basic theory of horn antenna and geometrical optics is studied. Four broadband double-ridged horn antennas and one optical lens are simulated by HFSS.2.The principle of impedance transformation is shown. Four convertors from coaxial line to double-ridged waveguide are designed in HFSS. These convertors are used as feeder system of lens antennas.3.Two kinds of methods are brought up in this article. Both of them can reduce the VSWR of lens antennas, infectively.4.These designed lens antennas are fabricated at last. After the testing and debugging, the four antennas are integrated into the "microwave lens equipment" for electromagnetic parameters measurement and microwave transmittance measurement.