Broadband Metamaterial‐Mushroom Antenna Array at 60 GHz Bands

Mushroom structures are widely applied for not only composite right/left‐handed (CRLH) dispersion of guided waves but also electromagnetic band gap (EBG) characteristic of surface waves. This chapter introduces a metamaterial‐mushroom antenna array in LTCC for broadband and high‐gain operation at millimeter wave (mmW) bands. The unique working principle of the CRLH‐mushroom antenna is illustrated to realize broad bandwidth with low profile. The EBG characteristic of surface waves is utilized to achieve low mutual couplings between the CRLH‐mushroom antenna elements in a large‐scale array. The exemplified 60 GHz LTCC metamaterial‐mushroom antenna array demonstrates the merits of low profile, broad bandwidth, high gain, high efficiency, low cross‐polarization levels, and distinctive self‐decoupling capability.