Abstract:
A programmable IF bandwidth is achieved in either a transmitter or receiver using fixed bandwidth filters. A minimum of two IF frequencies are used. A fixed bandwidth filter that is equal to or greater than the desired IF bandwidth is used at each IF. The Local Oscillators (LO's) are tuned to frequency convert the desired signal to a frequency that is offset towards one bandedge of the fixed IF filters. A first mixer and LO relocates the desired signal to one end of a first fixed IF filter. A second mixer and LO relocates the filtered signal to the opposite end of a second IF filter. The desired bandwidth is obtained as the sum of the frequency offset of the desired signal from the nearest bandedge of the first IF filter and the frequency offset of the desired signal from the opposite bandedge of the second IF filter.
Abstract:
A tunable RF filter, comprising: an emitter follower stage (2); and a common emitter stage (4); the common emitter stage (4) providing feedback to the emitter follower stage (2). The common emitter stage (4) may comprise a first transistor (Ti) being the only transistor of the common emitter stage (4); and the emitter follower stage (2) may comprise a second transistor (T2) being the only transistor of the emitter follower stage (2). A further tunable RF filter provides improved linearity, comprising: an emitter follower stage (22); a joint common emitter and emitter follower stage (24); and a gain stage (26); a common emitter output of the joint common emitter and emitter follower stage (24) providing feedback to the emitter follower stage (22), and an emitter follower output of the joint common emitter and emitter follower stage (24) providing an input to the gain stage (26).
Abstract:
An amplifier (2) has two transmission members (3, 4) connected in series whose logarithmic transmission functions (G, H) present linear flanks that depend on the frequency bijective function and have the same value but opposite signs, and control means (5) for shifting both flanks relatively to each other within the frequency range. The amplification rate of the amplifier may be controlled within the frequency range independently of frequency. Preferably, the capacity of a variable capacity diode is varied to shift the flanks.
Abstract:
Laser-Scanning-Mikroskop mit mindestens einem Scanner zur Änderung der Orientierung von Beleuchtungslicht, und mindestens einem Detektor zur Erfassung von Probenlicht, mit einer Verstärkerbaugruppe zur Verstärkung eines Detektionssignals eines Detektors DE, vorzugsweise einer APD (Avalanche-Photodiode) oder eines PMT (Photomultiplier), wobei die Verstärkerbaugruppe einen einstellbaren Kondensator KO beinhaltet, der abhängig von der Scangeschwindigkeit des Scanners einstellbar ist.
Abstract:
A tunable RF filter, comprising: an emitter follower stage (2); and a common emitter stage (4); the common emitter stage (4) providing feedback to the emitter follower stage (2). The common emitter stage (4) may comprise a first transistor (Ti) being the only transistor of the common emitter stage (4); and the emitter follower stage (2) may comprise a second transistor (T2) being the only transistor of the emitter follower stage (2). A further tunable RF filter provides improved linearity, comprising: an emitter follower stage (22); a joint common emitter and emitter follower stage (24); and a gain stage (26); a common emitter output of the joint common emitter and emitter follower stage (24) providing feedback to the emitter follower stage (22), and an emitter follower output of the joint common emitter and emitter follower stage (24) providing an input to the gain stage (26).
Abstract:
An exemplary modular musical instrument amplification system may comprise a chassis including a power supply, an input gain stage, a control processor and a plurality of modular slots. The modular slots are configured to receive any of a plurality of preamplifier modules for establishing an electrical communication therewith. The input gain stage has a modifiable response behavior and is in signal amplifying communication between at least one instrument input jack and the modular slots. The control processor is preferably in control communication between the modular slots and the input gain stage. Each preamplifier module has a respective input stage profile associated therewith. The control processor may be configured for sensing the input stage profile of a preamplifier module received in an active modular slot, and setting the response behavior based, at least in part, upon the respective input stage profile.
Abstract:
A transadmittance amplifier stage is coupled to a transimpedance amplifier stage to form a continuous time linear equalizer. The transadmittance amplifier stage has first and second gain paths and is configured to input a first signal and output a second signal. The first gain path is configured to provide a DC gain recovery and a first high frequency gain to the first signal. The second gain path is configured to provide a second high frequency gain to the first signal. The second signal is generated by the transadmittance amplifier stage based on the gain recovery of the first signal and the high frequency gains of the first signal. The transimpedance amplifier stage is configured to input the second signal from the transadmittance amplifier stage and convert the second signal to an output voltage signal.
Abstract:
A low noise amplifier including a variable gain amplifier stage configured to accept an input signal and to provide a load driving signal; a tunable bandpass filter connected as a load to the variable gain amplifier stage, wherein the bandpass filter includes a cross-coupled transistor pair, and at least one cross-coupled compensation transistor pair biased in a subthreshold region configured to add a transconductance component when the load driving signal is of a magnitude large enough to decreases a transconductance of the cross-coupled transistor pair; and, a controller circuit configured to tune the bandpass filter. The filter can be tuned in respect to the frequency and the quality factor Q.