Abstract: A fixed frequency continuously beam-steerable leaky-wave antenna in microstrip is disclosed. The antenna's radiating strips are loaded with identical shunt-mounted variable-reactance elements, resulting in low reverse-bias-voltage requirements. By varying the reverse-bias voltage across the variable-reactance elements, the main beam of the antenna may be scanned continuously at fixed frequency. The antenna may consist of an array of radiating strips, wherein each strip includes a variable-reactance element. Changing the element's reactance value has a similar effect as changing the length of the radiating strips. This is accompanied by a change in the phase velocity of the electromagnetic wave traveling along the antenna, and results in continuous fixed-frequency main-beam steering. Alternatively, the antenna may consist of two long radiating strips separated by a small gap, wherein identical variable-reactance elements are mounted in shunt across the gap at regular intervals.

Abstract: A monolithic non-linear transmission line and sampling circuit with reduced shock-wave-to-surface-wave coupling are presented herein. In coplanar-waveguide (CPW) technology, this reduced coupling is achieved by selecting properly the thickness of the semiconductor substrate, and by elevating the center conductor of the CPW above the substrate surface. The elevated center conductor is supported by means of conducting posts, and may be backed by a low-loss dielectric such as polyimide or silicon nitride. In coplanar-strip (CPS) technology, the reduction in coupling between shock waves and surface waves is achieved by controlling the substrate thickness as in the CPW case, and by elevating the coplanar strips above the substrate surface. The elevated strips are supported by a low-loss dielectric. The reduced coupling in both guiding media enhances the high-frequency performance of nonlinear-transmission-line-based circuits.

Abstract: A system and method for prescribing an amplitude distribution to a leaky-wave microstrip antenna having an array of radiating cells. The leaky-wave microstrip antenna includes a grounded element, a dielectric member coupled to the grounded element and a top conducting strip coupled to the dielectric member, the conducting strip including a first and second non-radiating conducting strip and a plurality of radiating cells. This distribution requires that the microstrip antenna possess a variable leakage-constant profile along its length, and is chosen so as to yield an H-plane power-gain pattern having low sidelobes. The leakage-constant profile is achieved by configuring the width and inter-cell spacing of the antenna radiating cells and keeping the phase constant fixed. The length or loading of the radiating cells may also be manipulated to achieve the desired leakage constant profile. This results in the desired distribution along the antenna's aperture and yields a power-gain pattern with low sidelobes.

Abstract: A system and method for prescribing an amplitude distribution to a leaky-wave microstrip antenna having an array of radiating cells. The leaky-wave microstrip antenna includes a grounded element, a dielectric member coupled to the grounded element and a top conducting strip coupled to the dielectric member, the conducting strip including a first and second non-radiating conducting strip and a plurality of radiating cells. This distribution requires that the microstrip antenna possess a variable leakage-constant profile along its length, and is chosen so as to yield an H-plane power-gain pattern having low sidelobes. The leakage-constant profile is achieved by configuring the width and inter-cell spacing of the antenna radiating cells and keeping the phase constant fixed. The length or loading of the radiating cells may also be manipulated to achieve the desired leakage constant profile. This results in the desired distribution along the antenna's aperture and yields a power-gain pattern with low sidelobes.

Abstract: A monolithic non-linear transmission line and sampling circuit with reduced shock-wave-to-surface-wave coupling are presented herein. In coplanar-waveguide (CPW) technology, this reduced coupling is achieved by selecting properly the thickness of the semiconductor substrate, and by elevating the center conductor of the CPW above the substrate surface. The elevated center conductor is supported by means of conducting posts, and may be backed by a low-loss dielectric such as polyimide or silicon nitride. In coplanar-strip (CPS) technology, the reduction in coupling between shock waves and surface waves is achieved by controlling the substrate thickness as in the CPW case, and by elevating the coplanar strips above the substrate surface. The elevated strips are supported by a low-loss dielectric. The reduced coupling in both guiding media enhances the high-frequency performance of nonlinear-transmission-line-based circuits.

Abstract: A system and method for providing improved isolation between sampling channels in a vector network analyzer and sampling circuit. A vector network analyzer sampling channel includes a non-linear transmission line, an isolation device, a band-pass filter, and a sampler. The nonlinear transmission line receives a continuous-wave driving signal and generates a shockwave from which a pulse signal is generated. The pulse signal is used to gate the sampler and thus sample an RF signal. The isolation device and band-pass filter provide reverse isolation for RF signals traveling in the reverse direction within the channel and prevent RF signal leakage between vector network analyzer channels. The isolation device may include an isolator, amplifier or other reverse isolation device, and is used in conjunction with a band-pass filter. The band-pass filter is used to pass a frequency band for driving the non-linear transmission line.