A multi-channel remote keyless entry (RKE) transponder having dynamically
re-configurable input channel selection, channel disable, settable
sensitivity for each channel, wake-up filter timing parameters, automatic
gain control hold, internal tuning capacitor selection for each channel's
antenna, minimum modulation depth requirement for input signal and
bi-directional talk-back. Programmable minimum modulation depth
requirement reduces false wake-up of the RKE transponder. An antenna for
each channel of the RKE transponder may be tuned with internal tuning
capacitors for improved range and receiver sensitivity. The internal
tuning capacitor parameters may be stored in a configuration register.
Gain of the channel may be fixed while the antenna is tuned. The antennas
may be de-queued for talk-back to a base station for low frequency
bi-directional communications. An external control device may dynamically
read from and write to the configuration registers via a serial
communications interface.