Abstract: A trainable transmitter is described that is capable of learning and replicating both AM and FM signals. The trainable transmitter also has the capacity to learn and replicate RF signals in both the 27 MHz to 40 MHz and the 250 MHz to 450 MHz frequency bands commonly used in European garage door openers. The trainable transmitter allows an individual to input an identification of the country in which the trainable transmitter will be operated such that the trainable transmitter may then transmit the learned signals at the maximum levels permitted for the identified county.

Abstract: A phased array antenna system includes a plurality of active radiating antenna elements each of which is driven by and each of which drives a transceiver module located closely adjacent thereto. Each transceiver module includes a high-power pulse signal-transmitting amplifier powered by a high-capacitance, low current dc rectifier system to minimize charging currents and provide very high pulse currents, and a low-noise amplifier for amplifying the received signal. The modules further include a transmit/receive switch, phase adjusting circuits in the input to the high-power signal-transmitting amplifier and in the output to the low-noise signal-receiving amplifier for normalizing the signal phase, and amplitude limiting means in the input of the low-noise signal receiving amplifier for protecting the low-noise amplifier during the transmit mode.