Abstract: An antenna consisting of a thin strip bent-wire monopole disposed on an artificial magnetic conductor (AMC) is loaded at the end opposite to the feed point with a distributed or lumped capacitance to achieve an electrically small antenna for use in handheld wireless devices. The capacitive load reduces the length of the antenna to smaller than one-quarter of a wavelength at a given frequency of operation without suffering a substantial loss of efficiency. This results in an easier integration into portable devices, greater radiation efficiency than other loaded antenna approaches and longer battery life in portable devices, and lower cost than use of a chip inductor.

Abstract: A patch antenna is composed of a segmented patch and MEMS switches which are built on a substrate. The patch segments of the segmented patch can be electrically connected to each other by the MEMS switches to form a contiguous patch and optional tuning strips and to connect or block RF between the contiguous patch and the optional tuning strips. When RF is connected between the tuning strips and the contiguous patch, the tuning strips increase the effective length of the contiguous patch and lower the antenna's resonant frequency, thereby allowing the antenna to be frequency tuned electrically over a relatively broadband of frequencies. When the tuning strips are connected to the patch in other than a symmetrical pattern, the antenna pattern of the antenna can be changed. In another aspect of the invention, the optional tuning strips are continuous structures that are formed by connecting patch segments using switches.

Abstract: A patch antenna is provided with one or more tuning strips spaced therefrom and RF switches to connect or block RF currents therebetween. When a control system for the antenna selectively connects and isolates RF currents between certain of the tuning strips and the patch, the tuning strips change the effective length of the patch and thus the antenna's resonant frequency, thereby frequency tuning the antenna electrically over a relatively broad band of frequencies. The control system includes circuitry for rapidly switching the antenna to a desired frequency with minimal delay and with superior isolation from the antenna, making it suitable for use in DAMA, TDMA, and other frequency hopping applications.

Abstract: A patch antenna is provided with one or more tuning strips spaced therefrom and RF switches to connect or block RF currents therebetween. When a conducting path for RF current is connected between the tuning strips and the patch, the tuning strips increase the effective length of the patch and lower the antenna's resonant frequency, thereby allowing the antenna to be frequency tuned electrically over a relatively broadband of frequencies. If the tuning strips are connected to the patch in other than a symmetrical pattern, the antenna pattern of the antenna can be changed. A feed network couples RF to the antenna and includes two hybrid couplers, one for providing the correct amplitude and phase of excitation at the feed probes, and the second for effectively dissipating reflected power due to antenna impedance mismatch.

Abstract: A patch antenna is provided with one or more tuning strips spaced therefrom and RF switches to connect or block RF therebetween. When RF is connected between the tuning strips and the patch, the tuning strips increase the effective length of the patch and lower the antenna's resonant frequency, thereby allowing the antenna to be frequency tuned electrically over a relatively broadband of frequencies. If the tuning strips are connected to the patch in other than a symmetrical pattern, the antenna pattern of the antenna can be changed.