A transmission circuit includes an array of subarrays of emitters with quasi-periodic spacing. A first subarray of emitters emits a source signal, and a second subarray of emitters emits the source signal. The first and second subarrays are separated by a subarray spacing that quasi-periodic, wherein the spacing between different subarrays is different. The quasi-periodic subarray spacing is to cause constructive interference of a main lobe of the emissions from the subarrays, and to cause non-constructive interference of sidelobes of the emissions. The spacing between emitters in the subarrays can vary from one subarray to another.