摘要:
This disclosure relates to the fabrication of components on a single crystal substrate. A method is disclosed of overcoming the problems encountered in defining etched features on a silicon substrate. In particular, there is disclosed a method of producing a multichip module comprising a silicon substrate having surface features for the placement of components. An organic dielectric is applied to the substrate prior to the use of an etchant whereby interconnects can be defined.
摘要:
The end (5) of an optical fibre (4) is held in alignment with an injection laser (3) by securing the fibre to an elongate support member (6) whose end nearer the injection laser is then laser beam welded (12) to a pair of slide members (8) that have previously been secured by laser beam welding (11) to leave a precisely dimensioned small gap between the support and slide members. The smallness of the gap minimises displacement of the fibre during the welding process. The end of the support member remote from the injection laser is secured by laser beam welding (16) to a plastically deformable saddle (10).
摘要:
PCT No. PCT/CA95/00328 Sec. 371 Date Jan. 26, 1996 Sec. 102(e) Date Jan. 26, 1996 PCT Filed Jun. 7, 1995 PCT Pub. No. WO95/35004 PCT Pub. Date Dec. 21, 1995A method of using the existing radio resources to automatically determine the current cellular topology is described. Wireless basestations are placed into a mode where they can transmit a signal which can be received by all of the base stations in range of the transmitting basestation. Each base station in the system serially broadcast a signal which is received by all other basestations within the range of the transmitting basestation. Each of the receiving radios determines the RSSI (Received Signal Strength Indication) at which they received the transmitted signal. The RSSI values are used to determine which base stations are physically co-located into cells and then determine the relative locations of the cells to each other.
摘要:
The isolation between stop and pass bands afforded by an optical fibre normally reflective Bragg grating (5) reflective over a waveband λ₃ in an optical fibre (2) is enhanced by preceding it with two blazed Bragg gratings (3, 4) that are spectrally selectively mode coupling respectively over wavebands λ₁ and λ₂, where the λ₃ waveband compasses the spectral waveband separating waveband λ₁ from waveband λ₂. The fibre is connected to an optical circulator (40) or one port of an optical 4-port 3dB coupler (50).
摘要:
This invention relates to radio communication systems and more especially to a base station arrangement comprising means to combine a number of signals input from receiving antennas. This invention is concerned with the combination techniques of spatially diverse systems and in particular seeks to provide a combination technique with performance close to optimal (maximal ratio) combiners but without the complexity. The invention provides a base station (10) arrangement which only processes the outputs from antennas (12) which contribute positively to the overall system carrier-to-noise ratio.
摘要:
An interferometric optical multiplexer (10) for use in optical communication systems and especially for use in optical communication systems employing fibre optical amplifiers is disclosed. The interferometric optical multiplexer has two input ports (12,14), an output port (16) and an output monitoring port (18). The interaction of the input signals is monitored by a photodetector situated in the monitoring part (18). In conjunction with a feedback circuit (24) wavelength separation of signals input at ports (12,14) is ensured. The system can be used to pump an erbium doped optical fiber amplifier.
摘要:
A reference voltage generator can provide RAMs (random access memories) with a reference voltage (generally mid-way between a supply voltage and a common potential), with improved follower characteristics. When the supply voltage and/or the load condition of the RAMs are significantly altered, the reference voltage is rapidly adjusted by dynamic switching FETs, being pulled down or up. Under balanced conditions when essentially no current flows in the switching FETs, overall power consumption is low.