Preface. Introduction, Fundamental Concepts, and Definitions. Solid-State Device Modeling. Harmonic-Balance analysis. Volterra-Series and Power-Series Analysis. Balanced Circuits. Diode Mixers. Diode Frequency Multipliers. Small-Signal Amplifiers. Power Amplifiers. Active Frequency Multipliers. Active Mixers. Oscillators. Index.

Nonlinear Microwave and RF Circuits

A pair of equally excited but oppositely sensed Archimedean two-wire spirals situated close to one another in the same plane-a doublet-is used to generate a linearly polarized field in which the direction of polarization and phase are controlled or varied independently of each other by rotation of the spiral radiators. An array of these doublets can be made to scan by rotation of the several spiral elements; an eight-doublet array which was made to scan over an 83\deg sector with small amplitude variation is discussed. A doublet fed from a ring network can be employed as a polarization diversity circuit. A virtual doublet is achieved by placing a single spiral in a fight angle trough. A preliminary scanning array comprising four spirals in a trough was made to scan \pm36\deg . The possibility of using a parasitic spiral in conjunction with a driven spiral for obtaining linear polarization of variable direction and phase is indicated. Also, a brief simplified analysis of the two-wire Archimedean spiral is presented, which leads to the concept of higher-order modes of radiation.

The Archimedean two-wire spiral antenna

A technique for designing impedance-transforming baluns is presented in this paper. It is based on the Marchand balun with two identical coupled lines. By varying the coupling factor of the coupled sections, a wide range of impedance transforming ratios can be achieved. In addition, a resistive network added between the balun outputs is proposed to achieve balun output matching and isolation. Microstrip baluns, matched at all ports, for transforming from a 50-/spl Omega/ source impedance to 40-/spl Omega/ as well as 160-/spl Omega/ load terminations are realized to demonstrate the technique.

Analysis and design of impedance-transforming planar Marchand baluns

Simulations and measurements are presented for an all-metal flared-notch array element in both single and dual-polarization configurations. The ultrawideband radiator exhibits an operational bandwidth of 12:1 for broadside scan and 8:1 bandwidth at a 45-degree scan in all planes, maintaining active VSWR<;2. The feed consists of a direct coax-to-slot-line transition that mounts directly into the base of the radiator. The all-metal flared-notches are machined from common metal stock and fed via SMA coaxial connectors. No soldering is required for any part of the design-including the feed-and assembly is simple and modular. The array parts are machined using a high-precision wire-EDM cutting technology, ensuring that measurements (in the 700 MHz-9 GHz range) are repeatable and give close agreement with theory, even through multiple assembly cycles of the modular construction system. This paper presents results for a 32-element linear array of horizontal elements and also an 8 × 8 planar array of dual-polarized elements, comparing measurements with full-wave simulations of the complete finite array structures.

Ultrawideband All-Metal Flared-Notch Array Radiator

We present a wideband tightly coupled dipole array (TCDA) with integrated balun and a novel superstrate consisting of printed frequency selective surface (FSS) for wide angle scanning. Although previous TCDAs have had decent scanning performance up to ±60°, use of dielectric superstrates are usually required, resulting in additional cost and fabrication complexity. In this paper, we replace the bulky dielectric layer(s) with periodic printed elements and yet achieve wide-angle and wideband impedance matching. The proposed approach provides superior performance of 6.1:1 bandwidth (0.5–3.1 GHz) with VSWR $E$ plane, ±70° in $D$ plane and ±60° in $H$ plane. The FSS, radiating dipoles and feed lines are designed and fabricated on the same vertically oriented printed circuit board, resulting in a low-cost and lightweight structure as compared to other low profile arrays. Measured scanning patterns of a $12 \times 12$ prototype are presented, showing good agreement with simulations.

N. Marchand

Papers

Transmission-line Conversion Transformers