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In this work, we present a comprehensive analysis of port impedance effects on a signal coupled across two-port networks, derive an equation to evaluate the impedances for a specified coupling, and demonstrate two beam-shaping active array antenna prototypes to validate the theory. In this context, the generalized S-parameters are theoretically studied and verified through an example. Subsequently, a closed-form equation is derived to accurately evaluate the port impedances that enable the achievement of a desired magnitude and phase of the signal coupling across the two-port network. The meaningfulness of all the potential results and the additional capabilities of derived equations are then discussed. With this understanding, a general modeling procedure is formulated to achieve the simultaneous amplification and phase shifting only through the active devices, without resorting to any additional passive circuitry. As a proof of concept, two 1 × 5 active array antenna prototypes are developed and fabricated at 5 GHz: one for broadside radiation with a sidelobe level of less than −20 dB requirement, and the other for flat-top radiation beam between −10° and 30°. They are integrated with a 1 × 5 Wilkinson power divider that is designed for radiation pattern measurements, and the corresponding results agree reasonably well with the simulated counterparts and theory, thereby proving the developed concept. Such solutions demonstrate the inherent advantages of being low-loss, compact, and efficient, which are essential for the next generation of wireless systems. [ABSTRACT FROM AUTHOR]

A generalized mesh-network equivalent model for a microstrip rectangular patch antenna (RPA), which is simple yet efficient is proposed, studied, and demonstrated in this article. The mesh-network equivalent model is established through the segmentation of RPA width and radiation parameters into $M$ sections, as well as the segmentation of RPA length into $N$ sections. A general design procedure to realize the mesh-network equivalent model is addressed and described for any number of RPA segmentations, as desired by specific applications. Subsequently, the proposed mesh-network equivalent model is used to accurately evaluate the input impedance responses at various feed positions along the length of RPA. In addition, to include the effects of a slot etched inside the RPA geometry, a generalized microstrip coupled line equivalent model is proposed, analyzed, and discussed in detail. Eventually, the microstrip coupled line model in conjunction with the proposed mesh-network equivalent model can accurately estimate the input impedance response of a slotted RPA, and has been verified for RPA with center slot, edge slot, and multiple slots as examples in this work. Two cases with multiport excitation of RPA are also analyzed and presented as a part of this work. For demonstration purposes, all these prototypes are designed, fabricated, and measured at 28 GHz. The proposed equivalent model-based results are validated by measured and simulated counterparts. Furthermore, the extension of the proposed mesh-network model to accommodate slots of smaller size inside RPA, RPA loaded with via, inverted-F antenna, and multimode operation are demonstrated and discussed through a comparison between mesh-network modeling results and simulation results. [ABSTRACT FROM AUTHOR]

This letter presents the integration of multiple active devices output port directly with the antenna for simultaneous active frequency multiplication and radiation. This eliminates the circuitry losses at the multiplied output frequency, which points to a significant advantage of the proposed unified integration space in addition to size reduction. Furthermore, active devices are configured in parallel to enhance the power handling capability of this unified module. Initially, the rectangular patch antenna is analyzed and presented as a potential design space for simultaneously accomplishing efficient radiation, output matching, and fundamental frequency suppression. Subsequently, a procedure to achieve the circuit–antenna unification is described through a prototype operating as a 14–28 GHz frequency doubler using two paralleled transistors. The fabricated prototype realizes the maximum conversion gain of 9 dB and fundamental frequency suppression of 14 dB from measurements. [ABSTRACT FROM AUTHOR]