Showing papers by "Motorola published in 1977"

A New Preferential Etch for Defects in Silicon Crystals

Abstract: A new preferential etch for (100) and (111) oriented, p‐ and n‐type silicon has been developed. Oxidation‐induced stacking faults, dislocations, swirl, and striations are clearly defined with minimum surface roughness or extraneous pitting. A relatively slow etch rate (∼1 μm per min) at room temperature provides etch control. The long shelf life of this etch allows the solution to be stored in large quantities.

Antenna array for a cellular RF communications system

Abstract: An array of antennas for a cellular RF communications system for providing communications to randomly placed transceivers in a given area. The antenna array includes a plurality of antenna sites located in the centers of cells. Each antenna site has a plurality of sectored antennas for providing a plurality of communication channels. A predetermined number of sites are used to constitute a subarray of cells to provide a set of communication channels and channel allocations are repeated from subarray to subarray. Channels are also so allocated as to minimize channel interference and optimize channel utilization. An omnidirectional antenna may be provided for each antenna site for signalling purposes.

Data communication system with random and burst error protection and correction

Abstract: A data communication system for use in the control and monitoring of mobile stations, for example, in a bus monitoring system, from a central station over a communication channel carrying both data and voice information. Information is encoded into digital messages having a start code followed by one or more data blocks. The start code identifies the beginning of the data block that follows and enables synchronization of clock circuitry to the received data frequency. The data blocks have N digital words with M binary bits where one word is a parity word and N-1 words are data words. Each of the data words has a data portion and parity portion coded for correction of at least one error. Reliability is enhanced by a data detector which discriminates between data and noise or voice to provide an indication of the presence of data. In transmitting the digital messages, the bits of the N words in each data block are interleaved to provide protection against error bursts.

Adjustable antenna arrangement for a portable radio

Abstract: An extendable half-wave dipole is capacitively coupled to a driven resonant helical antenna for use as on a hand-held, two-way portable radio, the helix being end fed. The dipole may be mounted adjacent to or collinear with the axis of the helix. The collinear mounting requires non-conductive portions on each end of the dipole. Optimum dimensional and performance characteristics are available without switching.

Detachable mounting clip arrangement for miniature portable apparatus or the like

Abstract: A detachable mounting clip arrangement is disclosed especially suited for application with miniaturized radio apparatus or the like of the type intended to be worn on the person such as on a belt or in the shirt pocket. The clip arrangement includes a tapered base plate assembly designed to insert within a recess formed by two convergent undercut side walls on the apparatus housing itself and retained therein by a ratchet like serrated section included on the housing surface which interacts with a resilient finger extending laterally from the base plate. The base plate itself is designed to support a conventional pivotable mounting clip assembly and associated torsion spring.

Directional antenna system including pattern control

Abstract: A directional antenna system is disclosed which selectively couples two radiating antenna elements to a transceiver through a selective phase, magnitude and matching network which is controlled by the output of a logic circuit. The network provides for equal magnitude current coupling between the transceiver and the two antennas while simultaneously selectively producing either positive or negative approximately 90° phase shifts between the two antennas to produce either of two discrete directive cardioid radiation patterns directed in substantially opposite directions. The logic circuit, in conjunction with a manual step switch, provides for a manually selecting either of the two cardioid radiation patterns, as well as producing a figure eight or an omnidirectional radiation pattern. For generating a transceiver omnidirectional pattern, one antenna is used and the other is connected to a standard broadcast band receiver. Matching networks are simultaneously selectively connected between the two antennas and the transceiver such that maximum power transfer and impedance matching is maintained for different radiation patterns. An automatic scanning switch is coupled to the logic circuit and provides for automatically selecting one of the cardioid radiation patterns as an optimum pattern in which the signal from the remote site is most strongly received by the transceiver. Indicating lights are provided to indicate which one of the radiation patterns is generated for the transceiver.

Control circuitry for a radio telephone

Abstract: A control circuitry for a radio telephone having a transmitter, a receiver, a cradle and a handset. The handset includes a first computer having a stored program control therein, a first memory, a telephone number display and a pushbutton pad. The cradle includes a second computer having a stored program control therein, a second memory, a plurality of control switches and radio telephone status indicators. A dialed number is entered into the handset memory from the pushbutton pad, under control of the handset computer. Then during a telephone call, the entered number is transferred from the handset computer to the cradle computer and transmitted by the cradle computer. Frequently called numbers can be stored in the handset memory or the cradle memory and later, can be readily recalled and transmitted. The last dialed number can be automatically retransmitted in a subsequent call.

Multifrequency microstrip antenna

Abstract: Three spaced apart electrically conducting discs coaxially mounted with dielectric material therebetween, one outside disc forming a ground plane and the center disc being driven by a lead through the ground plane to form a first microstrip antenna resonant at a first frequency, and the center disc forming a ground plane for the other outside disc which if fed by a lead extending through both of the other discs on a plane of zero electrical field for the second plate and along a radius orthogonal with a radius through the first lead, to form a second microstrip antenna resonant at a second frequency.

Sectored antenna receiving system

Abstract: A plurality of horizontally directive antenna sectors are arranged in configuration to receive signals from remote transmitters over a given angle in the horizontal plane. A scanning system is operative in one of several modes to sequentially couple each sector to a receiver. In its first mode, each sector is sequentially scanned with the output signal level therefrom being compared to a reference level. If the signal level on any sector exceeds the reference level the scanner activates to its second mode wherein scanning continues for a predetermined interval. At the end of the interval, scanning is inhibited and the receiver is coupled to that sector which produced the strongest signal level during the second mode scanning cycle. In the inhibit scan mode, if the signal level from the sector falls to a minimum level for a given time period the system reverts to the first scanning mode.

Reactor apparatus for plasma etching or deposition

Abstract: Plasma reactor apparatus which provides improved uniformity of etching or deposition. A uniform radio frequency (RF) field is established between two closely spaced parallel plates disposed within the reactor. One of the plates functions as a manifold for the reactant gases, mixing the gases and dispensing them through a regular array of orifices into the RF field between the plates. The uniformity results from a combination of the uniform field, the uniform dispersion of reactant gases, and the close proximity of the gas dispersal to the work pieces. The capacity of the apparatus can be increased by repeating the parallel plate structure in a stacked array of alternating grounded and RF energized plates.

Heat energized vapor adsorbent pump

Abstract: A solid matrix of microporous adsorbent is utilized to provide a barrier between two bodies of a gaseous mixture of which at least one constituent is a sorbable vapor. Appropriate application of heat at the opposing interfaces of the adsorbent barrier produces a partial pressure differential across the barrier. The adsorbent material is energized from a convenient heat source; for example, solar energy. The vapor pump of the invention may be used for environmental refrigeration and may be of the open or closed type. Other uses for the vapor pump are for producing a supply of pure water from low vapor content air or for drying air by removing the vapor content.

Standardized digital logic chip

Abstract: A standardized large scale integrated (LSI) array of standard logic cells on a single complementary metal oxide semiconductor (CMOS) chip. The pattern chosen for the layout of the standard logic cells provides very high cell density and, in combination with the "roadways" provided for power and data interconnects and the availability of "cross unders" within any cell chosen, very high utility ratios of the available cells. The standardized logic chip may be used to implement a large variety of logic circuit designs by the simple expedient of a single custom mask design for the metallization pattern for each unique use.

Adjustable transmission line filter and method of constructing same

Abstract: Transmission line filter adapted to respond to a predetermined frequency, having a resonator conducting layer with dielectric material on opposite sides thereof and a ground plane conducting layer on the outside surfaces of the dielectric material. The filter may be of the stripline or microstrip type having a resonator constructed so that it tends to operate at a frequency different from the desired frequency, and which is not accessible for trimming after the filter is constructed. The ground plane layer is accessible so that a portion thereof can be removed after the filter is constructed to change the electrical parameters of the line formed by the resonator and the ground plane layer to change the response frequency of the filter. Alternatively, conducting material can be added to an opening in the ground plane conducting layer to change the response frequency of the filter. The ground plane layer can be removed by a sand blast, laser beam or other means, and can be added by the use of conductive paint, to trim the frequency of the filter after it is constructed.

Method of semiconductor solar energy device fabrication

Abstract: This disclosure relates to a semiconductor solar energy device which is of the PN-type and utilizes a dielectric anti-reflective coating on the side of the device that faces the sunlight. The fabrication techniques used in making this semiconductor device include the use of a rough or textured pyramid shaped silicon surface beneath the anti-reflective coating to increase solar cell efficiency. Also, ion implantation is used to form the PN junction in the device. The ion implanted region located on the side of the device that is subjected to the sunlight is configured in order to permit metal ohmic contact to be made thereto without shorting through the doped region during sintering of the metal contacts to the semiconductor substrate. The dielectric anti-reflective coating, in one embodiment, is a composite of silicon dioxide and silicon nitride layers. The device is designed to permit solder contacts to be made to the P and N regions thereof without possibility of shorting to semiconductor regions of opposite type conductivity.

CMOS polarity reversal circuit

Abstract: Two P-channel MOS devices and two N-channel MOS devices are interconnected in a manner to provide a polarity reversal circuit. The circuit contains two input terminals and two output terminals. One of the output terminals is designated as a positive terminal while the other is designated as a negative terminal. Regardless of the polarity of voltage supplied to the input terminals, the positive voltage will always appear on the positive output terminal while the negative voltage will always appear on the negative output terminal.

Interface adaptor architecture

Abstract: A peripheral interface adaptor (PIA) circuit for data processing systems contains memory elements or control registers allowing modification under program control of the logical functions of the PIA. The peripheral interface adaptor includes a plurality of system data bus buffer circuits coupled to a system data bus and further includes peripheral interface buffer circuits coupled to a bidirectional peripheral data bus. The direction of data flow in the peripheral data bus is controlled by a data direction register. Data from the system data bus buffer is entered into an input register, and is transferred from there to an input bus coupled to the control register, a data direction register and a data register. Data from the peripheral data bus, the data direction register and the control register are transferred via an output bus to the system data bus buffers. Control signals are generated by select, read/write control, and register select logic which provides signals on a control bus coupled to the input register, the data register, the control register, and the data direction register to control data transfers between the various buses, registers, and buffer circuits.

ECG electrode impedance checking system as for emergency medical service

Abstract: A circuit for checking a plurality of impedances having a common connection point as for use in an emergency medical ratio, where the impedance of each ECG electrode contact is automatically and sequentially checked during the initial calibration transmission, using the AC non-polarizing signal which is also used as the ECG subcarrier for the medical data telemetry. The ECG telemetry calibration signal is also processed to provide a sequential switching control. Poor electrode contacts are indicated visually to the paramedic in charge and thus can be corrected before ECG telemetry begins.

Illumination apparatus for use in an illuminatable pushbutton keyset and the like

Abstract: An illumination apparatus which includes a plurality of indicating means arranged in rows, a light source, a light pipe assembly having a plurality of transparent light pipes disposed between the rows of indicating means, and means for distributing the light rays from the light source so that the indicating means are evenly and uniformly illuminated.

Portable radio antenna

Abstract: PORTABLE RADIO ANTENNA ABSTRACT OF THE DISCLOSURE An antenna for a hand-held radio transceiver includes first and second elements extending from the radio's case. The first element is comprised of a pair of series coupled members having electrical lengths of one-half and one-quarter wavelength, respectively, with the free end of the second member being coupled to the transmitter output. The second element couples to the radio's electrical ground and is configured to form a transmission line with the second member. The effective electrical length of the second element, including the influence of the elements parasitic coupling to the radio, is adjusted to be one-quarter wave-length. The resulting antenna structure minimizes surface currents across the radio's body, thereby substantially eliminating power loss caused by absorption in the user's body.

Programmable timer module coupled to microprocessor system

Abstract: A programmable timer module (PTM) is provided as a component of a microprocessor system in order to generate and measure varying time intervals under program control. The programmable timer module includes, in one embodiment, three independent 16-bit timers. Each timer includes a 16-bit counter and a 16-bit latch. The programmable timer module also includes an 8-bit status register and an 8-bit control register each of which may be coupled to an 8-bit bidirectional data bus of a microprocessor system. Selection circuitry is provided which permits the microprocessor to select either the control register or the status register. Information can be written into the control register; the operation is effected by means of read/write circuitry and a read/write input. Any one of the three timers can also be selected by means of the selection circuitry, and a 16-bit number can be written into the selected 16-bit latch. Reset circuitry resets the counter whenever the 16-bit latch is written into, and the counter counts until it reaches the number written into the 16-bit latch, whereupon the interrupt circuitry generates an interrupt signal and sets an appropriate interrupt bit in the status register, and also resets that counter. The counter continues counting at the appropriate clock rate after the interrupt so that time since the interrupt may be determined by the microprocessor. The outputs of the three counters can be selected as outputs of the programmable timer module.

Piezoelectric bimorph or monomorph bender structure

Abstract: A woven mesh of conductively coated stiff filaments is affixed between a first element deformable in response to an applied electronic signal and a second element which has substantially the same configuration as the first element and which may be electrically deformable also. The mesh serves as a center vane between two elements which allows the bender elements to move relative to each other. The bender is supported by peripheral tabs extending from the mesh. A bender structure is produced by coating a woven mesh of conductively coated filaments with an uncured solid epoxy. The mesh and two transducer elements are assembled together and heat and pressure applied to melt and then cure the epoxy, causing the conductive mesh material to make contact with and adhere to the faces of the transducer elements.

Charger/converter console with reel arrangement

Abstract: A console for charging a portable communications device and converting it for mobile operation can accommodate portable units of varying lengths. The contacts for the charging current are positioned by the insertion of a portable unit by means of a unique reel mechanism. Interconnection and latching are also activated by the insertion of the portable unit. The converter connector serves as a part of the latching and locking apparatus which makes the unattended portable essentially theft proof.

Structure and technique for achieving reduced inductive effect of undesired components of common lead inductance in a semiconductive RF power package

Abstract: An RF power transistor device, or package, which includes a transistor, a capacitor, an electrically insulating but thermally conducting substrate, a metallic ground lead member on the substrate having input output and common portions, a heat sink on which the substrate is mounted and, input and output microstrip conductor means mounted on the heat sink has the common lead inductive effect of at least one component of common lead inductance of the transistor reduced by tightly coupling the input ground current and the input current as by a film of dielectric material such as Kapton or Teflon of about one half mil in thickness. Alternatively the output current and the output ground current may be tightly coupled.

Programmable probe fixture and method of connecting units under test with test equipment

Abstract: A support houses a plurality of probes for guided movement relative to a printed circuit board unit under test fixedly mounted adjacent the support. Each probe is operatively associated with independent, pneumatically operated, piston and cylinder drive means for moving individual probes selected according to a predetermined program from a first retracted position to a second extended position. In the extended position only a continuous conductive path through the piston and cylinder is formed between the unit under test and an electrical interface for transmitting electronic signals therebetween. Several varieties of probes are provided for low and high frequency applications.

Method for encapsulating a solar cell array

Abstract: An enclosure for a solar cell array and a method of fabricating a solar cell module. The array is enclosed between a metal back plate and a cover glass. The edges of the enclosure are sealed by a pliable sealant material and a spring loaded bezel that is riveted or welded in place. The interior of the enclosure is filled with a potting material which surrounds and cushions the solar cell array. During the module fabrication a fixture supports the enclosure parts and provides a temporary edge seal to facilitate the potting procedure. Controlled flexure of the enclosure back plate and controlled spacing of the cover glass ensure a compressive loading of the potting material which eliminates possible delamination of the potting material in its subsequent usage.

Silicon purification process

Abstract: A process for producing semiconductor grade silicon. Metallurgical grade silicon, silicon dioxide, and silicon tetrafluoride are chemically combined at an elevated temperature to form silicon difluoride gas. The silicon difluoride gas is then polymerized, preferably in a two-step process. An initial small quantity of silicon difluoride polymers is formed at a first temperature. This initial polymerization removes most of the impurities that were present in the original metallurgical grade silicon and which were transported by the silicon difluoride gas. The bulk of the remaining silicon difluoride gas is then polymerized at a second, lower temperature. These polymers are substantially free from all impurities. The pure silicon difluoride polymers are then thermally decomposed at temperatures below 400° C. to form binary silicon fluoride homologues. The homologues can be distilled for even higher purity, or can be used or stored as formed. The binary silicon fluoride homologues produce pure silicon and silicon tetrafluoride when heated to a temperature between 400° C. and 950° C. The disproportionation of the homologues can be accomplished by chemical vapor deposition techniques onto heated substrates of silicon, metal, or quartz. This disproportionation will result in amorphous, polycrystalline, or monocrystalline silicon depending on the temperatures employed and on the substrate used for deposition.

Semiconductor lifetime measurement method

Abstract: A method for the measurement of minority carrier lifetime in semiconductor wafers, sheets and ribbons by purely optical means. The method does not require electrical or MOS contacts to the wafer, nor does it require any specific processing to facilitate measurement. The technique is non-destructive, and is applicable to any semiconductor wafer, with or without surface dielectric films (e.g., SiO 2 , Si 3 N 4 , Ta 2 O 5 ) as long as it has no metal films. This technique is fast, accurate, and of reasonable high resolution, so that it may be applied to evaluate the effects of specific process steps (e.g., ribbon growth, diffusion, oxidation, ion implantation, delectric deposition, annealing) in real time and hence serve as a production control technique as well as a research tool. By utilizing reasonable equipment sophistication, this technique should enable the measurement of lifetime over a wide range of values, covering the scale from high-speed bipolar devices and integrated circuits (˜10 -9 s) to power transistors and solar cells (˜10 -3 s).

Encapsulation housing for electronic circuit boards or the like and method of encapsulating

Abstract: A control device assembled on a circuit board is suitably encapsulated within a protective housing on a multiple unit basis especially suited for automation. A plurality of housings are arranged in an upright, side-by-side relation so that the associated circuit board may be inserted from a vertical direction and correctly positioned within the housing by a pair of guide rails and the action of gravity. The housings may then be suitably encapsulated utilizing a continuous and uninterrupted flow of encapsulating material. The housing itself is fabricated of a non-metallic, thermosetting material unaffected during subsequent operation in elevated ambient temperatures. The housing further includes a laterally extending lip or ledge which overlies a top portion of the next adjacent housing during assembly and encapsulation. Mounting holes are provided of a configuration to permit a wide variety of mounting locations.

Housing assembly for miniaturized battery operated electrical apparatus

Abstract: An improved housing assembly for housing miniaturized electrical or electronic apparatus, such as a radio receiver or monitor, is disclosed wherein a single piece housing is provided, open at the top for receiving an associated electrical chassis with self-contained battery compartment and a sound transducer. A control panel attached to the electrical chassis cooperates to overfit the open end of said housing to complete the overall assembly. The assemblage of the housing apparatus requires no screws, fasteners or special tools as the respective component parts effect a snap-fit with one another. A novel interlocking arrangement between chassis assembly and housing disguises the latching interfit therebetween, which nevertheless may be released by the insertion of a simple blade tool at the proper location. Complete shock mounting and protection from dust and dirt is effected by resilient gasket elements in cooperation with the housing and chassis assembly. A transparent lens cover is incorporated on a portion of the bottom panel to overlie an information placard referencing operational data but which, in addition, includes features which show if unauthorized access has been effected to the internal chassis assembly.