A Low-Profile Wideband LTCC Integrated Circularly Polarized Helical Antenna Array for Millimeter-Wave Applications

A low-profile wideband low-temperature co-fired ceramic integrated circularly polarized helical antenna array for millimeter-wave applications is presented. The major consideration of the antenna element design is to achieve good circular polarization and wide bandwidth when the helix has just about one turn which is beneficial for low profile. The turn is composed of 6×1/5-turn horizontal segments with straight-edge connections implemented by via holes. Then, a 2×2 helical antenna array with a dimension of 25×15×1.316 (0.15 λ0, is the wavelength at 35 GHz) mm3 was designed. The simulated results show that the proposed helical antenna array has a wide impedance bandwidth from 26.5 to 40 GHz for |S11| less than -13 dB and AR for AR less than 3 dB. The proposed antenna array was also measured and good agreement is achieved between the simulated and measured results