An antenna assembly, a receiver, and a system configured to superimpose a first received signal from a first antenna and an intermediate signal based on a second received signal from a second antenna onto a single cable. The antenna assembly includes a mixer and an adjustable local oscillator (ALO) that frequency shift the second received signal to generate the intermediate signal. The output frequency of the ALO is controlled by a control signal superimposed on the single cable that is output by the receiver. With this arrangement, a plurality of antennas or antenna elements can be connected to a receiver using a single coaxial cable. Such an arrangement is particularly desirable to manufacturers of automobiles and other vehicles. Also, the receiver can detect if the output frequency of the ALO needs to be adjusted, and so close-loop control of the output frequency is possible.