A 1 × 2 Taper Slot Antenna Array With Flip-Chip Interconnect via Glass-IPD Technology for 60 GHz Radar Sensors

Abstract

A low cost, broadband and compact antenna in package solution (AiP) is proposed for 60 GHz low-power radar sensor applications. Following a glass integrated passive device (Glass-IPD) manufacturing process, a compact low cost taper slot antenna (TSA) is designed on a substrate with a thickness beyond Yngvesson's range. To realize high gain and front-to-back ratio, the antenna is optimized by introducing a truncated ground. A 1 × 2 antenna array prototype is realized with a dummy transmission line chip in the dimension of 5 × 7.4 mm 2. Including the flip chip interconnect, the measured results demonstrate a 10 dB impedance bandwidth of 47.2 ∼ 67 GHz. The calculated gain is higher than 6.5 dBi in the end-fire direction over the entire 60 GHz band. Based on a physical RLC equivalent circuit, by co-design of the antenna with solder balls, the flip chip interconnect is compensated with a passive network. For the compensation network, its working bandwidth is from 0.1 to 67 GHz, while its insertion loss at 60 GHz is less than 0.2 dB. INDEX TERMS 60 GHz, antenna in package (AiP), CPW-slotline transition, flip-chip, glass integrated passive device (Glass-IPD), radar sensors, taper slot antenna (TSA).

A Review of 5G Front-End Systems Package Integration

“…The mechanical and process limitations of organic laminates from their low modulus and high CTE are addressed with emerging inorganic substrates, as listed in Table III. Glass substrates offer a wide range of Dk (3.7 -8) and Df (0.0003 for fused silica to 0.006 for alkaline-free borosilicate), smooth surface, good dimensional stability (< 2µm for 20mm substrates), large-panel scalability, ability to form finepitch through vias, stability to temperature and humidity, and tailorable CTE depending on the packaged components [28], [46][47][48][49]. Companies such as Samtec and Unimicron manufacture glass-based packages.…”

“…Their array preserves 14 dBi gain with 8 elements and 16.5 dBi gain with 16 elements over a 10-GHz bandwidth around 60 GHz. Glass-based AiP is also widely investigated especially in recent years [28], [49], [95], [96], because of its potential of electrical properties, dimensional stability, and panel scalability toward 500×500 mm 2 .…”

RF Glass Technology Is Going Mainstream: Review and Future Applications

“…Package-to-board transitions are conventionally implemented either using wire-bonding [109] or flip-chip techniques [110], [111], [92]. Fig.…”

“…Other examples of AiPs based on TGVs are holographic leaky-wave antennas, realized at 150 GHz [157] and at 77 GHz for automotive radar systems [158]; in both cases the metal structure is deposited on the glass wafer by PVD. As an alternative to TGVs, Xia et al proposed a tapered slot antenna for radar sensors at 60 GHz integrated in a flip-chip package [110]. When stacked onto an MMIC as a superstrate, a ca.…”