Abstract:
Methods and digital circuits providing frequency correction to frequency synthesizers are disclosed. An FLL digital circuit is provided that is configured to handle a reference frequency that is dynamic and ranges over a multi-decade range of frequencies. The FLL circuit includes a digital frequency iteration engine that allows for detection of disappearance of a reference frequency. When the digital frequency iteration engine detects that the reference frequency signal is not available, the oscillator generated frequency is not corrected, and the last value of the oscillator generated frequency is held until the reference frequency signal becomes available again.
Abstract:
A digitally implemented radio frequency sensor for physiology sensing may be configured to generate oscillation signals for emitting radio frequency pulses for range gated sensing. The sensor may include a radio frequency transmitter configured to emit the pulses and a receiver configured to receive reflected ones of the emitted radio frequency pulses under control of a microcontroller. The received pulses may be processed by the microcontroller to detect physiology characteristics such as motion, sleep, respiration and/or heartbeat. The microcontroller may be configured to generate timing pulses such as with a pulse generator for transmission of radio frequency sensing pulses. The microprocessor may sample received signals, such as in phase and quadrature phase analogue signals, to implement digital demodulation and baseband filtering of the received signals.
Abstract:
Certain aspects of the present disclosure provide techniques and apparatus for generating multiple oscillating signals. One example circuit generally includes a first voltage-controlled oscillator (VCO) having a first inductor and a second VCO having a second inductor in parallel with a third inductor, wherein the second and third inductors are disposed inside a loop of the first inductor and may behave as a magnetic dipole. The loop of the first inductor may be symmetrical, and a combined geometry of loops of the second and third inductors may be symmetrical. The coupling coefficient (k) between the first inductor and a combination of the second and third inductors may be small (e.g., k
Abstract:
A system includes a signal generator and a signal combiner. The signal generator is configured to output a first signal having a first frequency and to output one or more signals having the first frequency and having phases shifted relative to the first signal by predetermined amounts. The signal combiner is configured to combine the first signal and the one or more signals to output a frequency multiplied second signal having a second frequency. The second frequency is greater than the first frequency.
Abstract:
A semiconductor device that generates or detects terahertz waves includes a semiconductor layer that has a gain of the generated or detected terahertz waves; a first electrode connected to the semiconductor layer; a second electrode that is arranged at a side opposite to the side at which the first electrode is arranged with respect to the semiconductor layer and that is electrically connected to the semiconductor layer; a third electrode electrically connected to the second electrode; and a dielectric layer that is arranged around the semiconductor layer and the second electrode and between the first electrode and the third electrode and that is thicker than the semiconductor layer. The dielectric layer includes an area including a conductor electrically connecting the second electrode to the third electrode. The area is filled with the conductor.
Abstract:
Es wird ein Frequenzgenerator zur Erzeugung einer kontinuierlich in der Frequenz ansteigenden Frequenzrampe beschrieben. Der Frequenzgenerator umfasst einen Frequenzrampengenerator, der dazu ausgelegt ist,ein Frequenzsignal zu erzeugen,das eine Abfolge von mehreren aufeinander folgenden abfallenden und ansteigenden Teilrampen umfasst,einen Hochsetzfrequenzgenerator zur Erzeugung einer Mehrzahl von unterschiedlichen Hochsetzfrequenzsignalen, sowie einen Mischer, der dazu ausgelegt ist, die Teilrampen des Frequenzsignals mit auf die jeweilige Teilrampe abgestimmten Hochsetzfrequenzsignalen hochzumischen. Bei einer abfallenden Teilrampe liefert das untere Seitenband des so erhaltenen hochgemischten Signals eine hochgemischte ansteigende Teilrampe. Bei einer ansteigenden Teilrampe liefert das obere Seitenband des so erhaltenen hochgemischten Signals eine hochgemischte ansteigende Teilrampe. Der Frequenzgenerator ist dazu ausgelegt, die so erhaltenen hochgemischten ansteigenden Teilrampen zu einer kontinuierlich in der Frequenz ansteigenden Frequenzrampe zusammenzusetzen, wobei die Hochsetzfrequenzsignale für die verschiedenen Teilrampen so gewählt sind, dass sich die hochgemischten ansteigenden Teilrampen zu der kontinuierlich in der Frequenzansteigenden Frequenzrampe ergänzen.