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.

Coplanar waveguides and microwave inductors on silicon substrates

Abstract: Silicon has many advantages as a microwave substrate material including low cost and a mature technology. The aim of this paper is to evaluate the potential of using high-resistivity silicon as a low-cost low-loss microwave substrate through an experimental comparative study. Coplanar waveguides fabricated on Si, GaAs, and quartz substrates are tested and their characteristics are compared. Microwave spiral inductors and meander lines are also fabricated on various substrates, and their performance is also analyzed. The results demonstrate that the losses of a coplanar transmission line (CPW) realized on high-resistivity (3 k to 7 k /spl Omega/-cm) silicon substrates are comparable to the losses of a CPW realized on a GaAs substrate covered with insulators. Furthermore, measured unloaded Q's of microwave inductive structures on high-resistivity silicon substrates are comparable to the measured unloaded Q's of the same structures on GaAs and on quartz. This paper demonstrates that high-resistivity Si can be used as a microwave substrate. >

Extracting small-signal model parameters of silicon MOSFET transistors

Abstract: A novel approach to the extraction of small signal model parameters for silicon MOSFETs is described. This technique was developed to extract a high frequency model based only on S-parameter measurements to obtain both the intrinsic and parasitic resistance model parameter values of a small signal model. >

Ceramic bandpass filter.

Abstract: Un filtre ceramique passe-bande unique (100) se compose d'un bloc dielectrique (130) possedant un ou plusieurs trous (101-106) s'etendant de sa surface superieure jusqu'a sa surface inferieure et possedant egalement des electrodes d'entree et de sortie (124, 125) disposees chacune sur le bloc dielectrique a une distance predeterminee d'un trou correspondant. A single bandpass ceramic filter (100) comprises a dielectric block (130) having one or more holes (101-106) extending from its upper surface to its lower surface and also having electrodes of inlet and outlet (124, 125) each disposed on the dielectric block at a predetermined distance from a corresponding hole. Le materiau dielectrique est de preference en ceramique comprenant du BAO, du TuO2 et du ZrO2. The dielectric material is preferably ceramic comprising BAO, the TuO2 and ZrO2. Lorsqu'il n'y a qu'un trou dans le bloc dielectrique, les electrodes d'entree et de sortie peuvent etre disposees autour de ce trou. When there is a hole in the dielectric block, input and output electrodes can be disposed around the hole. Si il y a deux ou plusieurs trous dans le bloc dielectrique, une electrode peut etre disposee a proximite du trou a une extremite et l'autre electrode peut etre disposee a proximite du trou a l'extremite opposee du bloc dielectrique. If there are two or more holes in the dielectric block, an electrode can be disposed near the hole at one end and the other electrode can be disposed near the hole at the opposite end of the dielectric block. Celui-ci est entierement cuivre ou argente a l'exception des parties a proximite de chaque trou et des electrodes d'entree et de sortie. This is entirely copper or silver except for the parts near each hole and input and output electrodes. Chaque trou plaque constitue essentiellement un resonateur coaxial. Each plated hole essentially a coaxial resonator. Le couplage entre des resonateurs coaxiaux adjacents obtenu a l'aide des trous plaques peut etre regle grâce a des fentes (110-114) ou a des trous supplementaires disposes entre les elements. The coupling between adjacent coaxial resonators obtained using plated holes can be adjusted by means of slots (110-114) or additional holes disposed between the elements. Deux ou plusieurs filtres ceramiques passe-bande uniques peuvent etre couples pour obtenir un filtre presentant une selectivite superieure ou un filtre multi-bande pour combiner et/ou trier selon la frequence deux ou plusieurs signaux en un signal composite ou a partir de celui-ci. Two or more single bandpass ceramic filters can be coupled to obtain a filter having higher selectivity or a multi-band filter for combining and / or sorting by frequency two or more signals into a composite signal or from the latter .

Peak power and bandwidth efficient linear modulation

Abstract: In portable wireless communication systems, power consumption is of major concern. Traditional modulation and coding schemes have been designed from the standpoint of minimizing average power. However, for linear power amplifiers needed for spectrally efficient modulation formats, amplifier efficiency and hence power consumption are determined by the peak power of the transmitted signal. This paper looks into modulation formats which minimize peak power and retain high spectral efficiency. Peak power is broken into a sum (in terms of decibels) of average power and a peak-to-average power ratio, and a variety of modulation formats are evaluated in terms of peak power efficiency in both a Gaussian noise and Rayleigh fading channel. A generalized phase shift keying (PSK) modulation format is developed and shown to offer superior peak power efficiency relative to that of commonly used linear modulation formats. Two schemes are presented for reducing the peak-to-average power ratio of various modulation formats. First, data translation codes are used to avoid data sequences which cause large peaks in the transmitted signal. This approach was found to be most productive in quadrature amplitude modulation (QAM) formats. Finally, an adaptive peak suppression algorithm is presented which further reduces the peak-to-average power ratios of the PSK and generalized PSK formats. The peak suppression algorithm is also applicable to /spl pi//4-QPSK and was found to improve peak power efficiency of that format by about 1.25 dB over a Rayleigh fading channel.

Method and apparatus for cancelling spread-spectrum noise

Abstract: A spread-spectrum noise canceller is provided for cancelling user code noise from a spread-spectrum communication channel. The spread-spectrum noise canceller includes a receiver for receiving a spread-spectrum signal (114, 202 or 302) including a first (108, 204 or 304) and at least a second (110, 206 or 306) signal as well as a noise canceller operatively coupled to the receiver for reducing spread-spectrum noise in the first received signal (108, 204 or 304) by substantially processing the at least second received signal out of the received spread-spectrum signal (114, 202 or 302). In addition, a method is provided which cancels user code noise from a spread-spectrum communication channel. The method includes receiving a spread-spectrum signal (114, 202 or 302) including a first (108, 204 or 304) and at least a second (110, 206 or 306) signal and subsequently reducing spread-spectrum noise in the first received signal (108, 204 or 304) by substantially processing the at least second received signal 110, 206 or 306) out of the received spread-spectrum signal (114, 202 or 302).