摘要:
The invention comprises a frequency converter for converting an input frequency to an output frequency where the frequencies are widely separated. The system includes a free running output oscillator (30) adapted to be injection locked to an output frequency. A local oscillator (20) having a frequency near the output frequency, has its signal mixed with the input frequency to obtain a signal containing sideband frequencies which are both above and below the local oscillator frequency. Means (11 and 26) are provided for separating the sideband frequencies and applying one of the sidebands as an injection locking signal to the free running oscillator (30). In the preferred embodiment, the bandwidth of the free running output oscillator is centered above the highest sideband frequency if the sideband is lower in frequency than the frequency of the local oscillator or is centered below the lowest sideband frequency if the sideband is higher in frequency than the frequency of the local oscillator.
摘要:
Le mélangeur selon l'invention comprend deux conducteurs (20, 21) parallèles placés de part, et d'autre d'un substrat (13), une ou plusieurs diodes (27, 28) montées en série entre les premières extrémités (20a, 21 a) des deux conducteurs (20, 21), une entrée d'onde incidente S connectée entre la deuxième extrémité (20b) du conducteur (20) située sur la deuxième face (13b) du substrat (13) et une ligne de masse (14) située sur la première face, une entrée d'onde mélangeuse (OL) connectée à des moyens (24, 25) pour appliquer entre les extrémités de chacune des diodes (27,28) un champ électrique produit par l'onde mélangeuse, et une sortie d'onde mélangée (FI) connectée entre au moins une extrémité (29) d'une diode et la ligne de masse (14). L'extrémité (21 b) du conducteur (21) de la ligne bifilaire est laissée libre et est isolée électriquement de la ligne de masse par un espace (34). Application: mélangeurs hyperfréquences (2-18 GHz).
摘要:
A method and system for improving sensitivity of microwave and millimeter phase discriminators is disclosed. An exemplary embodiment of a phase discriminator includes two mixers inserted between two 90-degree hybrids. One hybrid splits the reference or LO signals into two signals of equal magnitude with a phase difference of 90 degrees. Similarly, the other hybrid splits the received RF signal into equal signals shifted 90 degrees in phase. One mixer receives an input set (e.g., LO and RF signals) with a zero-degree phase shift, and the other mixer receives the input set shifted in phase by 90 degrees. Thus, the leakage signals at the output of each mixer have the same magnitude but are 180 degrees apart in phase. The IF ports of the mixers are tied together, allowing the leakage signals of the mixers to combine destructively, thereby increasing isolation and sensitivity.
摘要:
Die vorliegende Erfindung betrifft ein Verfahren zur Erfassung der Amplitude und/oder Phasenlage eines zumindest teilweise intensitätsmodulierten Signals (P E (t)) sowie eine entsprechende Vorrichtung zur Durchführung des Verfahrens. Um ein Verfahren und eine Vorrichtung bereitzustellen, die es ermöglichen, die Nachteile des Standes der Technik zu vermeiden, werden erfindungsgemäß ein Verfahren und eine Vorrichtung zur Durchführung des Verfahrens vorgeschlagen, wobei das Verfahren die Schritte aufweist: i) Erfassen eines Momentanwerts des zumindest teilweise intensitätsmodulierten Signals (P E (t)), ii) Erfassen eines Momentanwerts eines ersten Referenzsignals (U m (t)), wobei das erste Referenzsignal (U m (t)) eine Frequenz (ω 2 ) hat, die sich von der Frequenz (ω 1 ) der Intensitätsmodulation unterscheidet, iii) Mischen des erfaßten Momentanwerts des zumindest teilweise intensitätsmodulierten Signals (P E (t)) mit dem erfaßten Momentanwert des ersten Referenzsignals (U m (t)), um einen Mischsignalwert (U Δ ) zu erhalten, iv) Erfassen eines Momentanwerts eines zweiten Referenzsignals (U I (t)), wobei das zweite Referenzsignal (U I (t)) eine Frequenz (Δω) hat, die sich sowohl von der Frequenz (ω 2 ) des ersten Referenzsignals als auch von der Frequenz (ω 1 ) der Intensitätsmodulation unterscheidet, v) Erfassen eines Momentanwerts eines dritten Referenzsignals (U Q (t)), wobei das dritte Referenzsignal die gleiche Frequenz (Δω) wie das zweite Referenzsignal hat, jedoch gegenüber dem zweiten Referenzsignal (U I (t)) phasenverschoben ist, vi) Mischen des Mischsignalwerts (U Δ ) mit dem erfaßten Momentanwert des zweiten Referenzsignals (U I (t)), um einen ersten Meßsignalwert zu erhalten, vii) Mischen des Mischsignalwerts (U Δ ) mit dem erfaßten Momentanwert des dritten Referenzsignals (U Q (t)), um einen zweiten Meßsignalwert zu erhalten, und viii) Berechnen der Amplitude und/oder Phasenlage des zumindest teilweise intensitätsmodulierten Signals (P E (t)) aus den beiden Meßsignalwerten.
摘要:
A circuit arrangement that reduces selected intermodulation. The circuit arrangement includes a signal amplifier coupled to a bandpass filter via an electrical path. Signal energy outside the passband is reflected back into the amplifier and causes intermodulation. The electrical path is constructed with a length that reduces intermodulation, where the length is an odd multiple of one-fourth the wavelength of a predetermined frequency in the passband. The length of the electrical path reduces intermodulation because certain signals reflected by the bandpass filter are approximately 180°, or an odd multiple thereof, out of phase. Energy of problematic signals that are near the edge of the passband or in the stopband is reduced, such as third order intermodulation product and pairs of signals that produce third order intermodulation products.
摘要:
An effective high frequency oscillator is made of a plurality of Josephson devices (31). A high frequency converter as a high frequency circuit is made of the high frequency oscillator, nonlinear superconductor devices, and transmission line. Josephson devices (31) are connected in parallel to make a superconductor module (J1-J4). Then superconductive modules (J1-J4) are connected in series for high frequency via a phase determining circuit such as a thin film type capacitor (C1-C3) to make the high frequency oscillator. Consequently, the high frequency oscillator is used as a local oscillator for a frequency converter. The high frequency system comprises a high frequency package housing a high frequency circuit, a cooling unit including a low temperature stage in thermal contact with the high frequency package, and a shielding case for housing the high frequency circuit and the low temperature stage. The high frequency system of the present invention provides a small-sized and power-saving high frequency circuit having operational stability.
摘要:
A zero-IF radio receiver circuit comprises an input filter (3), quadrature mixers (9,10), d.c.-blocking capacitors (24,26) and a demodulator (22). The circuit is partly integrated on a semiconductor chip and an inductive component of the input filter comprises one or more of the chip bond-wires. In order to compensate for the inevitable variation of the inductance of these bond-wires from circuit to circuit part of the signal from the local oscillator (12) is added to the input signal before its application to the input filter and the d.c. component of the resulting output from one mixer (10), which component is representative of the phase shift of the local oscillator signal produced by the input filter and hence of any tuning error of this filter, is applied to a tuning control input (30) of the filter to reduce the error. Alternatively the tuning control signal may be adjusted to maximise the sum of the squares of the d.c. components of the signals in the two IF channels and hence minimise the attenuation produced by the input filter.