Motorola

About: Motorola is a company organization based out in Schaumburg, Illinois, United States. It is known for research contribution in the topics: Signal & Communications system. The organization has 27298 authors who have published 38274 publications receiving 968710 citations. The organization is also known as: Motorola, Inc. & Galvin Manufacturing Corporation.

L-band transmitter using Kahn EER technique

Abstract: This paper describes a 20-W peak-envelope power linear L-band transmitter based upon the Kahn envelope-elimination-and-restoration technique. A double envelope-feedback loop assures high linearity. The radio-frequency (RF) power amplifier employs a two-stage monolithic-microwave integrated-circuit driver amplifier and a 20-W power amplifier biased for class-AB operation. The class-S modulator includes a high-speed comparator and 1/2-/spl mu/m heterojunction field-effect transistors in its output stage. A double envelope-feedback loop assures both high linearity and time-delay equalization for RF bandwidths to 150 kHz. With a two-tone signal, the transmitter achieves an efficiency of 56% at full power (41 dBm), and 35% at 18 dB into back-off. The third-order intermodulation distortions for a two-tone signal vary from -30 to -40 dBc over a 20-dB range of back-off. For quaternary phase-shift keying, the first and second adjacent-channel powers are -48 and -57 dBc.

Self-centering electrode for power devices

Abstract: An improved means and method for forming leads to a power device is provided by use of a one-piece leadframe on which the die is mounted and a separate connecting clip between the leadframe and the bonding pad on the semiconductor die. The leadframe has an alignment dimple or groove for receiving a mating alignment feature on one end of the connecting clip. The other end of the connecting clip is located over the bonding pad on the die. Solder is placed between die and the leadframe and between the connecting clip and the bonding pad and between the mating alignment surfaces on the clip and leadframe. When the solder is liquid during assembly the die and clip float thereon and automatically align by surface tension so that the die is centrally located on the die flag, the connection point on the clup is centered on the bonding pad and the mating alignment surfaces on the clip and leadframe are engaged. The self-aligning process is dominated by the mating alignment regions on the connecting clip and leadframe which have a larger area and solder wetted periphery than the other regions being soldered.

Generalized linear discriminant sequence kernels for speaker recognition

Abstract: Support Vector Machines have recently shown dramatic performance gains in many application areas. We show that the same gains can be realized in the area of speaker recognition via sequence kernels. A sequence kernel provides a numerical comparison of speech utterances as entire sequences rather than a probability at the frame level. We introduce a novel sequence kernel derived from generalized linear discriminants. The kernel has several advantages. First, the kernel uses an explicit expansion into “feature space”-this property allows all of the support vectors to be collapsed into a single vector creating a small speaker model. Second, the kernel retains the computational advantage of generalized linear discriminants trained using mean-squared error training. Finally, the kernel shows dramatic reductions in equal error rates over standard mean-squared error training in matched and mismatched conditions on a NIST speaker recognition task.

Wrist-carried radiotelephone

Abstract: An improved wrist-carried radiotelephone includes a first housing including a microphone, a display and a radio transceiver. A second housing includes a latch, a user interface, a speaker, and a removable battery. A flexible wristband has a first portion including an antenna extending downwardly and a latch clip at one end thereof operable to be received in the latch of the second housing. A second portion of the wristband includes electrical connections to connect the circuits of the first and second housing. The wristband includes support members to maintain the wrist-carrier radiotelephone in a predetermined configuration when the first portion of the wristband is unlatched from the second housing such that the speaker and microphone of the radiotelephone are at an optimum orientation in relation to a user's ear and mouth.