Abstract: A wireless base station has a transmitter and receiver. Transmission signals are applied to an antenna through a transmit bandpass filter that is tuned for a transmit band of frequencies. Received signals from the antenna are applied to the receiver through a receive bandpass filter that is tuned for a receive band of frequencies. An RF switching array consisting of four RF switches interconnects the output of the transmitter and the input of the receiver such that normal, loopback (self-test), and scanning modes can be performed. In the normal mode, the antenna is connected to the transmitter and receiver through the transmit and receive bandpass filters, respectively. The transmit and signal paths are effectively isolated from each other by three serially-connected open switches. In the loopback mode, the transmitter output is connected to the receiver input. In the scanning mode, the antenna is connected to the receiver through the transmit bandpass filter.

Abstract: A footwear shock-absorbing device comprises a lower receiving member, an upper receiving member, a plurality of fastening members, and a plurality of coil springs. The lower receiving member has a flat bottom provided with a plurality of columnar projections. The upper receiving member is located on the lower receiving member and provided with a flat top in contact with a footwear pad. The fastening members are fastened respectively at one end thereof with the flat top of the upper receiving member and at another end thereof with said columnar projections. The coil springs are fitted respectively over the fastening members such that both ends of the coil springs urge the flat top of the upper receiving member and the flat bottom of the lower receiving member, so as to enable the fastening members to locate at an upper dead point at such time when the fastening members are not exerted on by an external force.

Abstract: An adjustable collision avoidance signal for automobiles comprising a brake indicator signal, a mounting bracket, and a pedestal. Horizontal detents in the mounting bracket and complemental notches in the pedestal allow the mounting bracket to adjust vertically. The brake indicator signal is horizontally movable and pivotable with respect to the mounting bracket to which it is fixed. A light shade prevents stray reflections. The internal light source is located at the focal point of a parabolic reflector.