  Wearable on-body millimeter-wave (mmWave) radars can provide obstacle
detection and guidance for visually impaired people. However, their everyday
performance is hindered by the rigid form factor and limited scanning range. In
this article, we propose a low-profile, fast-scanning leaky-wave antenna (LWA)
operating in the unlicensed V-band (57-64 GHz) to be integrated for on-body
applications such as lightweight portable frequency-modulated continuous wave
(FMCW) radars. The proposed LWA consists of meandering microstrips that can
conform to the human body curvatures while maintaining beam-forming and
beam-scanning properties. Experimental results demonstrate that the planar LWA
achieves a realized gain above 10 dB with a fan-beam steering range in the
H-plane from -40{\deg} to 43{\deg} over the operating frequency band while the
half power beam-width (HPBW) is within 20{\deg}. Since for the foreseen
application the antenna is supposed to conform to the user's body, the
performance is also analyzed for a bent condition. The beam steering range
changes to -32{\deg} to 50{\deg} when placed on the knee (corresponding to 80
mm radius). Under bending conditions, the LWA exhibits a maximum degradation of
1.75 dB, while the HPBW increases to 25{\deg}. This shows that due to the small
size of the antenna, the impact of bending is low and the beam-forming and
beam-scanning property of the designed LWA remain intact. Furthermore, we
enable 2-D spatial scanning by employing an array of twelve LWAs with phased
excitation, extending the scanning range in the E-plane from -40{\deg} to
40{\deg}, while the HPBW remains below 20{\deg} across the operational
frequency range.
