Abstract: The present disclosure includes a discussion of a decision-directed clock recovery system which includes circuitry to prevent false-locking and accelerate acquisition on a known symbol patterns. The clock recovery system has at least two control circuits. Each control circuit has an effective bandwidth and also generates a clock signal. The clock recovery system samples the received data signal using the two clock signals, forming a corresponding first and second sampled signal. The sampled signals are used to generate corresponding symbol decisions. The symbol decision signals are processed to detect a known symbol pattern in the received data signal. Upon detection of the known bit sequence, the characteristics of the clock recovery system are modified, namely, the effective bandwidth of the control circuits are modified.

Abstract: A clock recovery circuit employs a method of and apparatus for adjusting the phase of a recovered clock signal. The clock signal is recovered from a received input signal. The clock recovery circuit generates a sampling clock signal which is synchronous with the received signal. Additionally, the phase adjustment apparatus generates at least two error signals which indicate the quality of the received signal at different sampling phases. The smallest error signal is referred to as the minimum error value. Each error signal is compared to the minimum error value, creating a corresponding normalized error magnitude signal. Each normalized error magnitude signal is processed to determine the desired phase of the sampling clock signal. Dependent upon the processing of the normalized error magnitude signals, the phase of the sampling clock signal is either shifted or maintained until the next sampling point.

Abstract: A solid source chemical vapor deposition apparatus and a CVD method for fabricating semiconductor devices are disclosed. In accordance with the process for fabricating semiconductor devices, a CVD reactor chamber having a solid reactant source apparatus coupled thereto is provided. The reactant source apparatus includes a container which can be heated in a controllable manner and which has a gas diffuser located in the container. The container is provided with gas input and output which are located so that a carrier gas can be passed through the gas diffuser and through a finely divided solid reactant source material which is positioned over the gas diffuser. The carrier gas together with any vapor derived from the solid reactant source material is conveyed from the outlet of the reactant source apparatus to the CVD reactor chamber.

Abstract: The present patent application includes a discussion of a signal compensation apparatus (119). The apparatus is implemented in a digital radiotelephone (101) having diversity receivers (111, 113). The signal compensation apparatus utilizes three control loops and a branch selection switch circuit to substantially diminish the undesired gain and DC offset present in the selected received data signal. Portions of the apparatus are implemented in a digital signal processor (DSP) (249) for rapid adjustment of the control loops when switching to a different receiver branch.

Abstract: The present disclosure includes a discussion of a radio receiver. The radio receiver has at least two operational states and includes a variable gain amplifier and at least two adaptive DC offset compensators (421, 427) to suppress undesired DC offset. The first operational state of the radio receiver (121) adjusts the adaptive DC offset compensator circuits (421, 427) to appropriate output levels in absence of an input signal to the radio (121). The second operational state receives the input signal through the radio receiver (121) and eliminates the undesired DC offset (309) from the received input signal with the adaptive DC offset compensator circuits (421, 427) and allows the received input signals to be processed.

Abstract: A wedge-shaped receptacle for mounting a noise cancelling microphone transducer (105) and a ringer alert transducer (107) within a housing (101) is disclosed. The receptacle (111) is molded from a flexible material providing efficient assembly of the transducers within two apertures in the receptacle (129 and 133). Gaskets (137 and 145), molded as part of the receptacle, provide an acoustic and weatherproof seal between the receptacle (111) and the housing (101) for each transducer. The two apertures (129 and 133), providing acoustic interface for the ringer alert transducer (107) and the microphone transducer (105), share the same opening (113) in the front face of the housing (101). The aperture (133) for the noise cancelling microphone (105) is also open to a second opening (115) in the bottom face of the housing (101) to cancel background noise. The receptacle includes channels (201 and 202) which allow back pressure release for the ringer alert transducer (107 ).

Abstract: A radio receiver (107) including at least two amplifier (245, 247, 207) stages each having adjustable gain. The receiver (107) generates a first and a second control signal (267, 229). In absence of receiving an input signal, the receiver (107) adjusts the gain of at least the first of the at least two amplifier stages (207) with said first control signal (229). Upon generation of the second control signal (267) the gain of the first of the at least two amplifiers stages (207) is maintained at a constant level. The gain of a second of the at least two amplifier stages (247) is adjusted with said first control signal (229), producing an output signal (269). A predetermined amplitude of the output signal (269) is maintained while receiving an input signal.

Abstract: In an exemplary embodiment, a communication device, such as a radiotelephone (100), has within its housing (106) an apparatus for electrically coupling an electroacoustic transducer (201), such as an earpiece, to radiotelephone circuitry (403). The apparatus comprises resilient conductive means, for example conductive barrel springs (213-216), abutting both the conductive contacts on the earpiece (214, 243) and the corresponding conductive contacts on a printed circuit substrate (205, 208, and 206, 207). A bracket (211) manually attached to the printed circuit substrate (203) positions the conductive barrel springs (213-216) while they are compressed between the earpiece (201) and the printed circuit substrate (203) during the assembly of the radiotelephone (100). A plurality of barrel springs (213-216) are used to provide redundant electrical coupling and stability for the earpiece (201). The apparatus advantageously provides for improved manufacturability and convenient replaceability of the earpiece (201).

Abstract: A hinge apparatus for a foldable telephone (100) includes a body portion (101) and a flip element (103). The flip element (103) is held in a closed (FIG. 3A) and a open (FIG. 3B) position relative to the body portion (101) by an enclosed follower (201) which follows recesses (301 and 303) in two hinge shafts (205 and 207) integral to the hinge portion (112) of the flip element (103). The apparatus is assembled along a common axis (233) from a single direction. The flip element (103) is held tight against a keypad (109) of the body portion (101) in its closed position (FIG. 3A). The flip element (103) is secured in its open position (FIG. 3B) with no excessive play.

Abstract: A receiver module 140 controls the amplitude of a random burst signal 200 in a TDMA system. A random burst signal 200 presence detector 330 detects when the random burst signal 200 has arrived during a timeslot reserved for the random access burst 200. After detection, a control processor monitors the signal strength or amplitude of the random access burst 200 for a predetermined time period, determines the amount of AGC attenuation required, and inserts the required AGC attenuation to control the amplitude of the random access burst 200 for the duration of the timeslot.

Abstract: A differential quadrature PSK receiver (100) recovers serial data in a forward and reverse direction in time using a forward and reverse mode PLL (232) and decoder switch (108). The DQPSK receiver (100) is particularly useful for recovering a packet of serial data (Rx) having a time-varying signal level and a relatively long duration. Sync words in the packet (Rx) or adjacent packets (Ry) provide starting points from which the data is recovered. The direction in time of data recovery is dependent on the quality of the time-varying signal level in the packet (Rx).

Abstract: A charging apparatus for a multiunit system includes a portable unit (101) and a base unit (103). The portable unit (101) includes first and second conductive contacts (119, 120) disposed on the portable unit (101) essentially opposite each other, and rechargable energy storage means (311) electrically coupled to the first and second conductive contacts (119, 120). The base unit (103) includes an indentation (124) formed in the base unit (103) and having a receiving surface shaped to receive at least a portion of the portable unit (101), first and second conductive protrusions (127, 129) extending outwardly beyond the receiving surface essentially opposite each other, and energy source means (131) electrically coupled to the first and second conductive protrusions (127, 129). The first and second conductive protrusions (127, 129) contact the first and a second conductive contacts (119, 120), respectively when at least a portion of the portable unit (101) is placed in the indentation (124).

Abstract: A communications receiver (103) comprising a carrier recovery apparatus having an adjustable response time loop filter (123) responsive to carrier signal parameters determined by a signal processor (141) is disclosed. Signal reception under fading conditions is improved by detecting the received signal parameters in an energy level determinator (207), a rate of change of energy level determinator (209) and a look-up table value (221) corresponding to a position of TDMA time clock (219).

Abstract: A container is provided for use in a clean environment, thereby allowing functional access to items such as chemicals stored within the container while minimizing contamination to the clean environment. A two-part unitary door includes an access plug and an entry plug. The plugs are separable from one another so that the container may be moved freely within the clean environment while the access plug seals the container from exposure to the clean environment, and the entry plug seals the clean environment from the exterior contaminated area. Structure is provided to enable functional access to the items stored within the container. In other embodiments, containers are provided for such objects as computers, oscilloscopes and the like.