Antenna structures and methods thereof for determining a frequency offset based on a differential magnitude

Abstract

A system that incorporates the subject disclosure may include, for example, a circuit for measuring from a first probe a first magnitude of radiated energy by an antenna, where the first probe serves as a first near field probe for measuring radiated energy from the antenna, measuring from a second probe a second magnitude of a transmit signal supplied to the antenna, where the second probe is placed at a location for measuring the transmit signal, comparing the first and the second magnitudes to generate a differential magnitude, and providing the differential magnitude to a controller for detecting an offset in an operating frequency of the antenna based on the differential magnitude, and for adjusting the operating frequency of the antenna to mitigate the offset. Other embodiments are disclosed.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]The present application claims the benefit of priority to U.S. Provisional Application No. 61 / 896,233 filed on Oct. 28, 2013, which is hereby incorporated herein by reference in its entirety.[0002]The present application claims the benefit of priority to U.S. Provisional Application No. 61 / 932,831 filed on Jan. 29, 2014, which is hereby incorporated herein by reference in its entirety.[0003]The present application claims the benefit of priority to U.S. Provisional Application No. 61 / 941,888 filed on Feb. 19, 2014, which is hereby incorporated herein by reference in its entirety.FIELD OF THE DISCLOSURE[0004]The present disclosure relates generally to antenna structures and methods thereof.BACKGROUND[0005]It is common for communications devices to have multiple antennas that are packaged close together (e.g., less than a quarter of a wavelength apart) and that can operate simultaneously within the same frequency band. Common examples of suc...

AI Technical Summary

Benefits of technology

The present patent is about antenna structures and methods for their use in communication devices. The technical effects of the patent include the ability to design antennas that can operate simultaneously within the same frequency band, and the use of connecting elements to connect multiple dipoles in an antenna structure. The patent also describes the use of a ground or counterpoise to improve the performance of the antenna. The disclosed antenna structures have improved scattering parameters, current ratios, gain patterns, envelope correlation, and other parameters that make them suitable for use in various communication devices.

Problems solved by technology

If the coupling is, e.g., −10 dB, 10 percent of the transmit power is lost due to that amount of power being directly coupled into the neighboring antenna.

There may also be detrimental system effects such as saturation or desensitization of a receiver connected to the neighboring antenna or degradation of the performance of a transmitter connected to the neighboring antenna.

Thus, while coupling may provide some pattern diversity, it has detrimental system impacts as described above.

The patterns are not uniformly omni-directional and change with frequency due to the changing magnitude and phase of the coupling.

The high isolation between antenna ports restricts interaction between the two amplifiers 1902, 1904, which is known to have undesirable effects such as signal distortion and loss of efficiency.

For example, problems such as pattern distortion and scan blindness (see Stutzman, Antenna Theory and Design, Wiley 1998, pgs 122-128 and 135-136, and 466-472) can arise from excessive inter-element coupling, as well as a reduction of the maximum gain attainable for a given number of elements.

In handset applications where the antennas are spaced at much less than ¼wavelength, mutual coupling effects in conventional antennas reduce the radiation efficiency of the array, and therefore reduce the maximum gain achievable.

This large impedance mismatch results in a very high VSWR, shown in FIGS. 27D and 27E, and as a result leads to the desired frequency rejection.

The efficiency-bandwidth trade-off is complex requiring E-M simulation tools for accurate prediction.

In turn, poor efficiency at the antenna translates to less battery life, as the PA must compensate for the loss.

This becomes a problematic as legacy phone antennas support pentaband operation but only bands 5 and band 8.

However, in this case, optimizing on S21 phase works poorly in the situation where near field probe is far from the antenna.

If, however, the frequency offset error is considered undesirable (or unacceptable), at step 5114 the adaptive antenna can be tuned by, for example, varying the electrical length of the antenna based on an Ltune value calculated from the difference in magnitude between the forward feed signal and the radiated energy of the antenna.

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