An ultrasonic matrix array probe comprising: a matrix array of transducer elements; a microbeamformer coupled to the transducer elements of the matrix array comprising: a plurality of controllable delays (112, 114, 116, 118, 120) coupled to elements of the matrix array to produce differently delayed transducer signals; a plurality of controllable switches (122, 124, 126, 132, 134, 136) coupled to combine differently delayed transducer signals to form a plurality of patch signals, wherein the microbeamformer can produce a maximum number of patch signals; a microbeamformer controller coupled to control the controllable delays and controllable switches; a probe connector which connects the matrix array probe to a system beamformer of an ultrasound system, the system beamformer having a given number of beamformer channels; and a probe cable coupled to the microbeamformer and the probe connector which couples the plurality of patch signals to the system beamformer, characterized in that the microbeamformer controller controls the delays and switches to produce the maximum number of patch signals when the given number of system beamformer channels equals or exceeds the maximum number, and to produce a number of patch signals which is less than the maximum number when the given number of system beamformer channels is less than the maximum number; wherein the microbeamformer controller is further coupled to receive one or more signals by means of the probe cable which identify the number of system beamformer channels. a matrix array of transducer elements; a microbeamformer coupled to the transducer elements of the matrix array comprising: a plurality of controllable delays (112, 114, 116, 118, 120) coupled to elements of the matrix array to produce differently delayed transducer signals; a plurality of controllable switches (122, 124, 126, 132, 134, 136) coupled to combine differently delayed transducer signals to form a plurality of patch signals, a plurality of controllable delays (112, 114, 116, 118, 120) coupled to elements of the matrix array to produce differently delayed transducer signals; a plurality of controllable switches (122, 124, 126, 132, 134, 136) coupled to combine differently delayed transducer signals to form a plurality of patch signals, wherein the microbeamformer can produce a maximum number of patch signals; a microbeamformer controller coupled to control the controllable delays and controllable switches; a probe connector which connects the matrix array probe to a system beamformer of an ultrasound system, the system beamformer having a given number of beamformer channels; and a probe cable coupled to the microbeamformer and the probe connector which couples the plurality of patch signals to the system beamformer, characterized in that the microbeamformer controller controls the delays and switches to produce the maximum number of patch signals when the given number of system beamformer channels equals or exceeds the maximum number, and to produce a number of patch signals which is less than the maximum number when the given number of system beamformer channels is less than the maximum number; wherein the microbeamformer controller is further coupled to receive one or more signals by means of the probe cable which identify the number of system beamformer channels.