A 4-channel ultra wideband timed array transmitter chipset is reported in 0.13 mum CMOS technology that is suitable for radar and imaging applications. It consists of an all-digital timing control and impulse generation circuitry chip and a set of UWB pulse forming switches. The all-digital chip creates desired delayed versions of an input pulse sequence, which may be coded and/or pulse position modulated, for all 4 channels. It also converts the input pulse sequence to an impulse sequence. The all-digital chip can be directly connected to an antenna array to generate non-carrier based (impulse) waveforms. It can also control the timing of UWB pulse forming switches that are connected to an antenna array to generate carrier based (pulsed sinusoid) waveforms. The delay difference resolution and maximum delay difference between the impulse sequences at adjacent channels are 180ps and 880ps, respectively. The UWB pulse forming switches achieve sub-200ps rise/fall time with isolation higher than 40dB and insertion loss better than 4dB between DC-6GHz. The proposed UWB timed array architecture eliminates the need for area and power hungry true time delay circuitry that would have been otherwise needed for beam-forming.