Abstract: A novel and useful apparatus for and method of improving antenna matching and reducing mismatch loss for a VHF receiver such as an FM receiver. The invention can be used in a very low cost implementation of a single chip radio such as used in cellphone applications. The impedance of the low cost VHF antenna in cellphone application can dramatically vary across time, frequency and depending on the human body proximity resulting in a large mismatch loss. The adaptive antenna matching mechanism uses dynamically configurable on-chip variable capacitors to provide a custom matching network with the external inductor in a pi-network configuration. The variable ranges of the on-chip capacitors enable adaptation in a closed loop manner so that the optimum SNR is achieved thus ensuring minimum mismatch loss. The mechanism measures RSSI and SNR and, using a novel adaptive calibration mechanism, adjusts the internal matching network capacitors such that the mismatch loss is minimized.

Abstract: An enhanced antenna apparatus suitable for use with portable wireless devices. The antenna of the present invention comprises a conductive sleeve having an inner core that can accommodate one or more signal wires passing therethrough. The conductive sleeve functions as the radiating element of the antenna. The length of the conductive sleeve is made an integer multiple of one half the wavelength of the desired frequency. By passing the signal wires through the conductive sleeve the mutual impedance between the antenna itself and signal wires passing through the antenna is eliminated. Alternatively, the antenna can be constructed on a printed circuit board using elongated printed pattern on the top and bottom layers of the printed circuit board. The length of the printed pattern is made an integer multiple of one half wavelength of the desired frequency.

Abstract: A novel RF antenna and method of manufacture thereof is disclosed. With this novel antenna the energy radiates in all directions including both left hand and right hand polarizations. In one embodiment of the invention, the antenna consists of two equal size rectangularly shaped conductive sheets positioned in parallel with each other. The side dimensions are nearly a half wavelength of the center frequency. The rectangle is nearly a square with one dimension slightly larger than the other. The feed point is at any of the corners. The difference in side dimensions cause the antenna to resonate at two adjacent frequencies, one slightly above the working frequency and the other slightly below. This creates a phase difference between the orthogonal modes of operation at the working frequency. A 90 degree phase difference generates circular polarization.