摘要:
A circuit comprising a differential transmission line and eight switches provides non-reciprocal signal flow. In some embodiments, the circuit can be driven by four local oscillator signals. The circuit can be used to form a gyrator. The circuit can be used to form a circulator. The circuit can be used to form three-port circulator than can provide direction signal flow between a transmitter and an antenna and from the antenna to a receiver. The three-port circulator can be used to implement a full duplex transceiver that uses a single antenna for transmitting and receiving.
摘要:
In some embodiments, circuits for providing Class-E power amplifiers are provided, the circuits comprising: a first switch having a first side and a second side; a first Class-E load network coupled to the first side of the first switch; a second Class-E load network; and a second switch having a first side and a second side, the first side of the second switch being coupled the second side of the first switch and the second Class-E load network. In some embodiments, the circuits further comprise: a third switch having a first side and a second side; a third Class-E load network coupled to the first side of the third switch; a fourth Class-E load network; and a fourth switch having a first side and a second side, the first side of the fourth switch being coupled the second side of the third switch and the fourth Class-E load network.
摘要:
Full duplex transceivers are provided, the transceivers comprising: a transmitter section that includes an analog portion having analog baseband signals and a digital portion having digital baseband signals; a receiver section that includes an analog portion having analog baseband signals and a digital portion having digital baseband signals; an analog self-interference canceller that, in response to the analog baseband signals in the analog portion of the transmitter section, produces analog cancellation signals that cancel first self-interference in the analog baseband signals in the analog portion of the receiver section; and a digital self-interference canceller that, in response to the digital baseband signals in the digital portion of the transmitter section, produces digital cancellation signals that cancel second self-interference in the digital baseband signals in the digital portion of the receiver section.
摘要:
Methods and systems may identify a vector or a vector configuration, such as a combination of electrodes, for monitoring ischemia. The method may include: selecting a first combination of sensors as a first candidate to be used for monitoring ischemia; detecting a shift in a ST segment of one of an electrocardiogram and a cardiac electrogram using the first candidate; selecting a second combination of sensors as a second candidate to be used for monitoring ischemia; detecting a shift in a ST segment of one of an electrocardiogram and a cardiac electrogram using the second candidate; comparing the ST shifts for the first and second candidates; and identifying one of the first and second candidates for monitoring ischemia based on the comparison. A multi-electrode implantable cardiac device may include a controller configured to effectuate such functions.
摘要:
Cardiac activity is sensed over a plurality of heart beats defining a beat set. For each beat in the set, it is determined whether the beat is a non-classified beat (e.g., paced beat, a beat outside of a specified heart rate range or a PVC), or a classified beat. For each classified beat, it is determined whether the beat is a non-detect beat, a minor beat or a major beat. Counts of classified beats, non-classified beats, major beats, minor beats, and non-detect beats are maintained. The beat set is declared to be one of a non-classified set, a major set, a minor set or a non-detect set based on the relative counts of classified beats, non-classified beats, major beats, minor beats, and non-detect beats. Over a period of time, counts of beat-set types are maintained and entry into and exit from ST episodes are determined based on these beat-set counts.
摘要:
In accordance with some embodiments, non-reciprocal circulators are provided, the circulators comprising: a 3λX/4-long ring section having a first end and a second end, wherein λ is an operating wavelength of the non-reciprocal circulator; and a N-path filter having a first port, a second port, and N-paths, each of the N-paths being connected to the first port and the second port. In some of these embodiments, the 3λ/4-long ring section includes a transmit port, an antenna port, and a receive port. In some of these embodiments, the transmit port is λ/4 away from the antenna port. In some of these embodiments, the antenna port is λ/4 away from the receive port. In some of these embodiments, the receive port is at the first port of the N-path filter.
摘要:
Circuits and methods for antenna-based self-interference cancellation are provided. In some embodiments, circuits for antenna-based self-interference cancellation are provided, the circuits comprising: a transmit antenna having a transmit port that receives a transmit signal; a receive antenna having a receive port that is cross-polarized with respect to the transmit port and having an auxiliary port that is co-polarized with respect to the transmit port; and a termination connected to the auxiliary port that reflects a signal received at the auxiliary port as a reflected signal, wherein the reflected signal counters interference caused by the transmit signal at the receive port.
摘要:
A plurality of receivers each having: an RF amplifier having an RFAMP input coupled to an antenna and having an RFAMP output; a capacitor having a CAP first side connected to the RFAMP output and a CAP second side; a passive mixer coupled to the RFAMP input, the CAP second side, and the output of a local oscillator phase shifter; an operational transconductor amplifier having an OTA input connected to the CAP second side and having an OTA output; a feedback resistor connected between the OTA input and the OTA output; a baseband transconductor having a BBGM input connected to the OTA input and a BBGM output; a cancelling transconductor having a CANCELLER output connected to the BBGM output and having a CANCELLER input; and an attenuator between the OTA output and the CANCELLER input, wherein the OTA output of each of the plurality of receivers are connected together.
摘要:
Self-interference cancellers are provided. The self-interference cancellers can include multiple second-order, N-path Gm-C filters. Each filter can be configured to cancel self-interference on a channel of a desired bandwidth. Each filter can be independently controlled using a variable transmitter resistance, a variable receiver resistance, a variable baseband capacitance, a variable transconductance, and a variable time shift between local oscillators that control switches in the filter. By controlling these variables, magnitude, phase, slope of magnitude, and slope of phase of the cancellers frequency responses can be controlled for self-interference cancellation. A calibration process is also provided for configuring the canceller.
摘要:
A phase shifter and method include a hybrid coupler being ground shielded. The hybrid coupler with reflective terminations connected to the hybrid coupler is configured to phase shift an applied signal wherein the reflective terminations include a parallel LC circuit.