摘要:
Une fréquence porteuse est modulée en fréquence avec une onde triangulaire et émise à partir d'un détecteur (52) en direction d'une cible (56) se déplaçant par rapport au détecteur, la reflexion (58) à partir de la cible (56) est reçue et mélangée (62) avec une partie du signal émis (54). Deux harmoniques au minimum de la fréquence de modulation sont filtrées (74, 74a) à partir de la sortie du mélangeur. Chaque harmonique est détectée de manière synchrone (84, 84a) avec une harmonique de la même fréquence pour obtenir un signal doppler qui est détecté et introduit dans un comparateur (92). Chaque harmonique et son enveloppe doppler correspondante atteignent un pic d'amplitude à une distance de la cible propre à chacune d'elles. Quand l'amplitude du doppler d'une harmonique est supérieure à celle du doppler d'une autre harmonique, une distance prédéterminée par rapport à la cible est signalée par le comparateur.
摘要:
A laser diode module comprises a rectangular, box-like metal casing having a bottom (B), whereas an even number of guide pins (1-14) are passed through the bottom (B) in a standardized DIL order and no less than one guide pin (5) is electroconductively connected to the bottom (B). In addition to the laser diode (LD) itself the module further includes a Peltier cooler (TEC) and a thermal metal base carrier (BC) coupled thereto, which base carrier accommodates the laser diode (LD), a photodiode (PD), a support (S) for the glass fibre (F) and a thermistor (TH). In order to render this laser diode module suitable for use in communication systems with bit rates that exceed by far 1 Gbit/s, the said guide pin (5) has inside the casing a portion in the form of a rod with a constant cross-section and with no less than one flat side face which over its entire surface has an electroconductive coupling with the relevant long sidewall (SW₁) of the casing, an electroconductive interconnecting strip being provided between the head face of the rod and the base carrier (BC)
摘要:
A divider circuit arrangement in which in order to avoid dividing by zero the divisor (V d ) is modified by the addition of an extra signal (X a ) to form a modified divisor V′ d = V d + X a and the dividend (V i ) is modified by the addition of the product of the quotient (V o ) and the extra signal (X a ) to form a modified dividend V′ i = V i + V o X a . A particular but not exclusive application of this divider circuit arrangement is in normalising an output signal from a dual branch receiver (not shown).
摘要翻译:一种除法器电路装置,为了避免除数除数(Vd),通过添加额外的信号(Xa)来修改,以形成修正除数V min d = Vd + Xa,并且除数(Vi)被修改 通过添加商(Vo)和额外信号(Xa)的乘积以形成修改的分红V min i = Vi + VoXa。 该分频器电路装置的一个特殊的但并不排他的应用是将来自双分支接收器(未示出)的输出信号归一化。
摘要:
A system for transmitting an n-level data signal (d k ) at a given symbol rate 1/T comprises a data transmitter (1), a transmission channel (2) and a data receiver (3) with an equalizer (30) of the decision feedback type. By arranging this equalizer (30) for forming an estimate ( c k ) of a virtual m-level data signal ( Ck ) instead of the output signal (b k ) of the data transmitter (1) error propagation in the equalizer (30) is considerably reduced without thereby appreciably adding to the implementation-complexity of the system.
摘要:
In certain types of microwave ovens, e.g. ovens of the single-wall type, the manufacturing of the oven cavity (10) involves the forming of at least one groove-shaped recess (16) in at least one of the cavity walls (14). In order to substantially eliminate the disturbing effect of this recess (16) on the microwave field pattern in the oven cavity (10), a reflecting element in the shape of an elongated strip (18) of conductive material is provided in a position at the entrance opening of the recess (16), as seen from the oven cavity (10). The conductive strip (18) is preferably covered by dielectric material, e.g. in the shape of a dielectric plate (20) that also serves as support for the strip (18), and this strip (18) is so dimensioned and disposed at the opening of the recess (16) that it substantially reflects all incident microwave radiation coming from the oven cavity (10) at the operational frequency of the microwave oven.
摘要:
A microwave oven comprises an oven cavity (10) bounded by conductive walls (11-16) and means (17-19) situated such that microwave energy is fed from above into the oven cavity (10). A bottom plate (20) of a dielectric material is situated above the conductive bottom wall (16), on which plate (20) food to be heated (21) is placed. Two conductive ridges (24, 25) project from the condcutive bottom wall (16), which ridges (24, 25) are situated adhacent and in parallel to the respective shorter conductive side walls (12, 14). The dielectric bottom plate (20) is placed and dimensioned, in consideration of its dielectric constant, such that a trapped TM resonant mode is generated in the space between the upper surface of the bottom plate (20) and the conductive bottom wall (16). This trapped TM resonant mode is excited via the bottom plate (20) and the ridges (24, 25) by the microwave field above the bottom plate (20), microwave energy from the TM resonant mode within and below the bottom plate (20) will "leak" into the food (21) owing to its higher dielectric constant, whereby the food (21) will be subjected to an appreciable heating from below.
摘要:
The invention relates to a method of enciphering information-containing digital data signals with the aid of enciphering keys and of deciphering a message thus enciphered, utilizing the same key. For usages in which high demands are made on the quality of enciphering the conventional method - the EX-OR adding together of clear text and key text on a bit basis - has shortcomings. The invention has for its object to provide a very reliable method with which furthermore the propagation of errors caused by any transmission errors is prevented. This is accomplished in that the (clear) text characters to be enciphered are processed using an enciphering key which is derived from a key text and that the nature of the processing operation performed on the clear text characters is determined by an instruction command which is also derived from the key text.