Abstract: An ultra-wideband, large-current radiator consisting of a ground plane and two electric monopoles: a wide radiating monopole orthogonal to the ground plane, and a thin monopole orthogonal to the ground plane and normally displaced from the wide monopole. The frequency-independent low impedance of the antenna allows a small voltage to generate a large current. The wide radiating monopole may be a flat sheet, or a sheet of parallel bars. Shielding by the wide monopole suppresses radiation from the thin monopole into a sector of space into which the monopole radiation characteristic of a well-formed impulse in response to a voltage step is desired. In one preferred embodiment, two parallel flat sheets or a conducting cylinder is used as the wide radiating monopole, further shielding radiation from the thin monopole.

Abstract: A network of localizers determines relative locations in three-dimensional space to within 1 cm by measuring propagation times of pseudorandom sequences of electromagnetic impulses. The propagation time is determined from a correlator which provides an analog pseudo-autocorrelation function sampled at discrete time bins. The correlator has a number of integrators, each integrator providing a signal proportional to the time integral of the product of the expected pulse sequence delayed by one of the discrete time bins, and the non-delayed received antenna signal. Using pattern recognition the arrival time of the received signal can be determined to within a time much smaller than the separation between bins. Because operation of standard CMOS circuitry generates noise over a large frequency range, only low-noise circuitry operates during transmission and reception. A stage in the low-frequency clock uses low-noise circuitry during transmissions and receptions, and standard circuitry at other times.

Abstract: A network of localizers determines relative locations in three-dimensional space to within 1 cm by cooperatively measuring propagation times of pseudorandom sequences of electromagnetic impulses. Ranging transmissions may include encoded digital information to increase accuracy. The propagation time is determined from a correlator circuit which provides an analog pseudo-autocorrelation function sampled at discrete time bins. The correlator has a number of integrators, each integrator providing a signal proportional to the time integral of the product of the expected pulse sequence delayed by one of the discrete time bins, and the non-delayed received antenna signal. With the impulses organized as doublets the sampled correlator output can vary considerably in shape depending on where the autocorrelation function peak falls in relation to the nearest bin. Using pattern recognition the time of arrival of the received signal can be determined to within a time much smaller than the separation between bins.