  We have developed a compact, wide-bandwidth, dual-polarization
cloverleaf-shaped antenna to feed the CHIME radio telescope. The antenna has
been tuned using CST to have smaller than -10dB s11 for over an octave of
bandwidth, covering the full CHIME band from 400MHz to 800MHz and this
performance has been confirmed by measurement. The antennas are made of
conventional low loss circuit boards and can be mass produced economically,
which is important because CHIME requires 1280 feeds. They are compact enough
to be placed 30cm apart in a linear array at any azimuthal rotation.
