摘要:
The device has a single strip having a first end, a second end, a length and a width. The first end of the strip is curved toward the second end of the strip to form a loop having a height. The length is approximately 10 mm, the width is approximately 5-8 mm, and the height is approximately 0.8-1.2 mm. The loop is preferably fabricated from copper. The loop is mounted directly to a test instrument such as a computer controlled impedance analyzer or network analyzer. The test instrument measures the inductance and resistance of the loop with no thin film sample placed therein, and then measures the inductance and resistance of the loop containing the sample under test. From these measurements, the device ultimately derives the permeability of the sample under test. The method for measuring the complex permeability of thin films at ultra-high frequencies includes the steps of recording the residual inductance and resistance for the loop empty; measuring the total inductance and resistance for the loop loaded with the sample under test; determining the change in resistance by subtracting the resistance of the loop without any sample from the resistance when the loop is loaded with the sample under test; determining the change in inductance by subtracting the inductance of the loop without any sample from the inductance when the loop is loaded with the sample under test; and calculating permeability.
摘要:
Improved techniques for characterizing, adjusting and optimizing the overall performance of a wireless network. In an illustrative embodiment, the overall network performance for a particular network configuration is characterized by a vector with two components, one representing network coverage and another representing network capacity. Network coverage is defined by the likelihood of service under load, including interference, and may be further weighted by traffic density. Network capacity is defined by an amount of traffic with a given spatial distribution that can be served at a given overall target-blocking rate. The overall network performance may be characterized using a two-dimensional capacity/coverage diagram which plots overall network performance vectors, each including a network capacity component and a network coverage component, for various network configurations. The overall network performance may be improved or optimized with respect to a given subset of network parameters by using an algorithm that proposes potential network configurations and evaluates them with respect to their overall network performance.
摘要:
A method of producing an amplified signal decomposes a signal into at least a first part and second part using at least one amplitude threshold. The first part includes a portion of the signal with a lower peak-to-average power ratio than the signal based on the amplitude threshold. The second part includes a portion of the signal beyond the amplitude threshold. At least the first part and the second part are amplified to produce an amplified first part and amplified second part, which are combined to produce an amplified signal.
摘要:
A method and transmitter for amplifying at least first and second diversity-encoded signals, where each of the first and second diversity-encoded signals may represent information of a first signal to be transmitted using transmit diversity. Amplification of the first and second diversity-encoded signals may be shared between at least two amplifiers, and amplification for a second signal, to be amplified and transmitted without using transmit diversity, may be shared between the at least two amplifiers.
摘要:
The technique of amplifier sharing is implemented in a system designed to accommodate transmit diversity. In one embodiment of the invention, the amplifiers are shared 1) to amplify a first and a second diversity-encoded signal, each of which represents the information a first signal that is to be transmitted using transmit diversity, and 2) to amplify a second signal to be transmitted without using transmit diversity. The first and second diversity-encoded signals are used to form a first and a second composite signal. Each composite signal is amplified in a different one of two power amplifiers. Each amplified composite signal is then used to form an amplified first diversity-encoded signal and an amplified second diversity-encoded signal. The first and second composite signals can also be formed using the second signal. Each composite signal is then amplified in a different one of the two power amplifiers and the two amplified composite signals are used to form an amplified second signal. In another embodiment of the invention, the first and second composite signals can be formed in the digital domain. Each composite signal is digitally pre-distorted and then modulated onto a transmission frequency signal, such as an RF signal. Each pre-distorted composite signal is then amplified in the respective amplifier.
摘要:
A signal amplification system involves decomposing a signal into two or more parts, amplifying the parts and then combining the amplified parts to produce the amplified signal. The decomposition can be done such that the resulting parts have characteristics that are amenable to efficient amplification. For example, decomposition of the signal to be amplified can be done using at least one threshold. The first part of the signal to be amplified can be formed by the portion of the signal within the threshold. As such, because the first part forms a signal with a lower PAR, the first part of the signal can be amplified more efficiently than the original signal. The second part of the signal can be formed by the portion of the original signal beyond the threshold. Because the second part is mostly zero, the second part can also be amplified efficiently, for example with a class C type amplifier which does not dissipate any energy when the input signal is zero.
摘要:
The identification of wireless communication base stations in a region of high base station density is effected using a specific identification signal pattern transmitted by the base stations. In particular, each base station transmits a signal having a pattern with at least two time phase shifts relative to at least one time benchmark. The combination of these phase shifts allows identification of the transmitting base station. Since a plurality of phase shifts leads to a concomitantly larger number of phase shift combinations, the capacity to identify base stations is enlarged.
摘要:
The identification of wireless communication base stations in a region of high base station density is effected using a specific identification signal pattern transmitted by the base stations. In particular, each base station transmits a signal having a pattern with at least two time phase shifts relative to at least one time benchmark. The combination of these phase shifts allows identification of the transmitting base station. Since a plurality of phase shifts leads to a concomitantly larger number of phase shift combinations, the capacity to identify base stations is enlarged.
摘要:
A signal notching system reduces signal peaks by notching the peak of a signal above a threshold to produce a notched signal. The notched signal is then filtered to produce a resulting signal with a reduced peak amplitude. For example, in an implementation where the signal is represented by signal samples, the peak notching system first locates a peak sample that is beyond a threshold, such as a sample representing a positive peak sample of a peak above the threshold. Once a peak sample is located, the peak notching system adjusts the peak sample by an amount which is a function of the amount that the peak sample is beyond the threshold, effectively creating a notched signal with a one sample notch at the peak. The peak notching system filters the notched signal to fill in the notch to produce a signal with a reduced peak.
摘要:
The disclosed superconducting multipole RF filter comprises a multiplicity of coupled circular disk resonators designed for operation in the TM 010 mode. The disk resonators are arranged in a co-axial stack, with a circular metal spacer sandwiched between any two neighboring disk resonators. Each metal spacer has a central through-aperture, with a conductive member disposed in the through-aperture and electrically connecting the two neighboring disk resonators that are sandwiching a given metal spacer. A disk resonator comprises two circular members, each circular member comprising a circular dielectric substrate, exemplarily a LaAlO.sub.3 wafer. Superconducting layers (typically YBCO) are disposed on each major surface of the substrate. The two members are joined together such that conductive layers (typically gold) electrically connect the two outside superconducting layers. The disclosed RF filter has good power handling capability, is compact, has good heat removal and relatively simple tuning. It can, for instance, be advantageously used as transmit filter in base stations of a wireless communication system.