I am new to RF field and trying to use an Archimedean Spiral Antenna design from this paper to capture 915MHz RF for the P2110B power harvester chip. The estimated antenna impedance is 188 Ohm (see page 5), whereas the chip's unbalanced RF input expects a 50 Ohm antenna (see page 4).
How can I match the impedance of the antenna to the RF input and how the antenna should be connected to the chip since it has no ground plane? Should one end of the antenna be connected to the GND pins on both sides of the RF pin?
There will be a dedicated directional RF power transmitter (not just ambient RF) emitting at 915MHz center frequency. The plan is to transfer energy across some surface (up to 2 inch thick), so, please, share your thoughts if you think there is a better approach.