Abstract: A baseband-derived RF predistortion system using a lookup table having coefficients extracted at baseband and then applied at RF by means of a vector modulator. The architecture combines the narrowband advantage of envelope predistortion with the accuracy of baseband predistortion, and including compensation for memory effects. A polynomial-based alternative is also described.

Abstract: A baseband-derived RF predistortion system using a lookup table having coefficients extracted at baseband and then applied at RF by means of a vector modulator. The architecture combines the narrowband advantage of envelope predistortion with the accuracy of baseband predistortion, and including compensation for memory effects. A polynomial-based alternative is also described.

Abstract: A high performance and cost effective method of RF-digital hybrid mode power amplifier systems with high linearity and high efficiency for multi-frequency band wideband communication system applications is disclosed. The present disclosure enables a power amplifier system to be field reconfigurable and support multiple operating frequency bands on the same PA system over a very wide bandwidth. In addition, the present invention supports multi-modulation schemes (modulation agnostic), multi-carriers and multi-channels.

Abstract: A remote radio head unit (RRU) system for achieving high efficiency and high linearity in wideband communication systems is disclosed. The present invention is based on the method of adaptive digital predistortion to linearize a power amplifier inside the RRU. The power amplifier characteristics such as variation of linearity and asymmetric distortion of the amplifier output signal are monitored by a wideband feedback path and controlled by the adaptation algorithm in a digital module. Therefore, embodiments of the present invention can compensate for the nonlinearities as well as memory effects of the power amplifier systems and also improve performance, in terms of power added efficiency, adjacent channel leakage ratio and peak-to-average power ratio. The present disclosure enables a power amplifier system to be field reconfigurable and support multi-modulation schemes (modulation agnostic), multi-carriers, multi-frequency bands and multi-channels.

Abstract: In some embodiments, a method of reducing adjacent channel power ratio and compensating memory effects of multi-channel wideband communication systems using multiplexing modulation techniques is provided. The method includes generating an address from samples of a baseband input signal of a communication system. The method also includes retrieving from a memoryless lookup table an entry in accordance with the address. The method further includes pre-equalizing the baseband input signal, the pre-equalization depending on one or more magnitudes of the input signal. The method still further includes multiplying the pre-equalized baseband input signal and the lookup table entry.

Abstract: An efficient baseband predistortion linearization method for reducing the spectral regrowth and compensating memory effects in wideband communication systems using effective multiplexing modulation technique such as wideband code division multiple access and orthogonal frequency division multiplexing is disclosed. The present invention is based on the method of piecewise pre-equalized lookup table based predistortion, which is a cascade of a lookup table predistortion and piecewise pre-equalizers, to reduce the computational complexity and numerical instability for desired linearity performance with memory effects compensation for wideband transmitter systems.

Abstract: In accordance with the present invention, there is provided a semiconductor package (e.g., a QFP package) including a uniquely configured leadframe sized and configured to maximize the available number of exposed leads in the semiconductor package. More particularly, the semiconductor package of the present invention includes a generally planar die pad or die paddle defining multiple peripheral edge segments. In addition, the semiconductor package includes a plurality of leads. Some of these leads include exposed bottom surface portions which are provided in at least one row or ring which at least partially circumvents the die pad, with other leads including portions which protrude from respective side surfaces of a package body of the semiconductor package. Connected to the top surface of the die pad is at least one semiconductor die which is electrically connected to at least some of the leads.

Abstract: In accordance with the present invention, there is provided a semiconductor package (e.g., a QFP package) including a uniquely configured leadframe sized and configured to maximize the available number of exposed leads in the semiconductor package. More particularly, the semiconductor package of the present invention includes a generally planar die pad or die paddle defining multiple peripheral edge segments. In addition, the semiconductor package includes a plurality of leads. Some of these leads include exposed bottom surface portions which are provided in at least two concentric rows or rings which at least partially circumvent the die pad, with other leads including portions which protrude from respective side surfaces of a package body of the semiconductor package. Connected to the top surface of the die pad is at least one semiconductor die which is electrically connected to at least some of the leads.

Abstract: A RF-digital hybrid mode power amplifier system for achieving high efficiency and high linearity in wideband communication systems is disclosed. The present invention is based on the method of adaptive digital predistortion to linearize a power amplifier in the RF domain. The present disclosure enables a power amplifier system to be field reconfigurable and support multi-modulation schemes (modulation agnostic), multi-carriers and multi-channels. As a result, the digital hybrid mode power amplifier system is particularly suitable for wireless transmission systems, such as base-stations, repeaters, and indoor signal coverage systems, where baseband I-Q signal information is not readily available.

Abstract: A power amplifier using N-way Doherty structure with adaptive bias supply power tracking for extending the efficiency region over the high peak-to-average power ratio of the multiplexing modulated signals such as wideband code division multiple access and orthogonal frequency division multiplexing is disclosed. In an embodiment, the present invention uses a dual-feed distributed structure to an N-way Doherty amplifier to improve the isolation between at least one main amplifier and at least one peaking amplifier and, and also to improve both gain and efficiency performance at high output back-off power. Hybrid couplers can be used at either or both of the input and output. In at least some implementations, circuit space is also conserved due to the integration of amplification, power splitting and combining.

Abstract: A power amplifier using N-way Doherty structure for extending the efficiency region over the high peak-to-average power ratio of the multiplexing modulated signals such as wideband code division multiple access and orthogonal frequency division multiplexing is disclosed. In an embodiment, the present invention uses a dual-feed distributed structure to an N-way Doherty amplifier to improve the isolation between at least one main amplifier and at least one peaking amplifier and, and also to improve both gain and efficiency performance at high output back-off power. Hybrid couplers can be used at either or both of the input and output. In at least some implementations, circuit space is also conserved due to the integration of amplification, power splitting and combining.

Abstract: An efficient peak cancellation method for reducing the peak-to-average power ratio in wideband communication systems uses repeated clipping and frequency domain filtering to achieve a desired peak-to-average power ratio for wideband code division multiple access and orthogonal frequency division multiplexing signals. The maximum magnitude of the filtered pulse is determined by a scaling factor which permits eliminating several iterations while still achieving convergence to the targeted peak-to-average power ratio, thereby reducing computational load and saving hardware resources. This results in improved performance in terms of error vector magnitude, adjacent channel leakage ratio and peak-to-average power ratio.

Abstract: A baseband-derived RF predistortion system using a lookup table having coefficients extracted at baseband and then applied at RF by means of a vector modulator. The architecture combines the narrowband advantage of envelope predistortion with the accuracy of baseband predistortion, and including compensation for memory effects. A polynomial-based alternative is also described.

Abstract: A power amplifier using N-way Doherty structure for extending the efficiency region over the high peak-to-average power ratio of the multiplexing modulated signals such as wideband code division multiple access and orthogonal frequency division multiplexing is disclosed. In an embodiment, the present invention uses a dual-feed distributed structure to an N-way Doherty amplifier to improve the isolation between at least one main amplifier and at least one peaking amplifier and, and also to improve both gain and efficiency performance at high output back-off power. Hybrid couplers can be used at either or both of the input and output. In at least some implementations, circuit space is also conserved due to the integration of amplification, power splitting and combining.

Abstract: A RF-digital hybrid mode power amplifier system for achieving high efficiency and high linearity in wideband communication systems is disclosed. The present invention is based on the method of adaptive digital predistortion to linearize a power amplifier in the RF domain. The power amplifier characteristics such as variation of linearity and asymmetric distortion of the amplifier output signal are monitored by the narrowband feedback path and controlled by the adaptation algorithm in a digital module. Therefore, the present invention could compensate the nonlinearities as well as memory effects of the power amplifier systems and also improve performances, in terms of power added efficiency, adjacent channel leakage ratio and peak-to-average power ratio. The present disclosure enables a power amplifier system to be field reconfigurable and support multi-modulation schemes (modulation agnostic), multi-carriers and multi-channels.

Abstract: An efficient baseband predistortion linearization method for reducing the spectral regrowth and compensating memory effects in wideband communication systems using effective multiplexing modulation technique such as wideband code division multiple access and orthogonal frequency division multiplexing is disclosed. The present invention is based on the method of piecewise pre-equalized lookup table based predistortion, which is a cascade of a lookup table predistortion and piecewise pre-equalizers, to reduce the computational complexity and numerical instability for desired linearity performance with memory effects compensation for wideband transmitter systems. Therefore, the present invention could reduce the computational load, which saves hardware resources in an implementation and improve performance, in terms of adjacent channel power ratio.

Abstract: In accordance with the present invention, there is provided a semiconductor package which includes a generally planar die paddle defining multiple peripheral edge segments and including at least two slots formed therein and extending along respective ones of a pair of the peripheral edge segments thereof. The semiconductor package further comprises a plurality of first leads which are segregated into at least two sets disposed within respective ones of the slots included in the die paddle. In addition to the first leads, the semiconductor package includes a plurality of second leads which are also segregated into at least two sets extending along respective ones of at least two peripheral edge segments of the die paddle in spaced relation thereto. Electrically connected to the top surface of the die paddle is at least one semiconductor die which is electrically connected to at least some of each of the first and second leads.

Abstract: In accordance with the present invention, there is provided a semiconductor package which includes a generally planar die paddle defining multiple peripheral edge segments and including at least two slots formed therein and extending along respective ones of a pair of the peripheral edge segments thereof. The semiconductor package further comprises a plurality of first leads which are segregated into at least two sets disposed within respective ones of the slots included in the die paddle. In addition to the first leads, the semiconductor package includes a plurality of second leads which are also segregated into at least two sets extending along respective ones of at least two peripheral edge segments of the die paddle in spaced relation thereto. Electrically connected to the top surface of the die paddle is at least one semiconductor die which is electrically connected to at least some of each of the first and second leads.