22 results about "Fractional bandwidth" patented technology

Bandpass filters for a target communications band extending between a lower band edge and an upper band edge are disclosed. A bandpass filter includes one or more shunt resonators and one or more series resonators connected in a ladder filter circuit, wherein a relative difference between the anti-resonance and resonance frequencies of each acoustic resonator is greater than a fractional bandwidth of the target communications band. A first capacitor is connected in parallel with a first shunt resonator from the one or more shunt resonators, and a second capacitor connected in parallel with a first series resonator from the one or more series resonators.

The invention discloses a 3dB bridge which comprises a multi-layer dielectric body, and a first coupling line and a second coupling line are arranged on the two opposite sides of the multi-layer dielectric body respectively and are overlapped on the wide side of a coupling part. The first coupling line and the second coupling line are respectively divided into parallel finger-shaped conductor sections at the coupling part, and the adjacent finger sections correspond in a cross-layer staggered manner to form a multi-scale coupling channel of the same coupling part; corresponding input ends and output ends are respectively led out from the first coupling line and the second coupling line; and a parasitic resonance unit which is electromagnetically coupled with the finger section is arranged in the multilayer dielectric body at a distance d1 from the transverse edge of the coupling part. The 3dB bridge enables in-band coupling to be self-balanced along with frequency, a parasitic unit compensates a band edge in situ in a near field, the problem that single-scale coupling and boundary cannot be quantized is solved, wider fractional bandwidth, flatter amplitude and phase and improvement of band edge directivity and port isolation are achieved, repeatability and mass production consistency are ensured through d1, d2, T, k1 and k2 constraints, and the 3dB bridge adapts to co-fired ceramic packaging.

An antenna device having a plurality of antennas arranged on a vehicle along a width direction intersecting with a traveling direction of the vehicle, the antenna device including: a first antenna that receives radio waves of a first frequency; and a second antenna that is positioned on the outside of the first antenna in the width direction of the vehicle and that is for radio waves of a second frequency band having a fractional bandwidth narrower than the first frequency.

A broadband Doherty power amplifier is disclosed. A Doherty power amplifier includes a main power amplifier and a peaking amplifier. In contrast to conventional approaches that combine outputs from the main and peaking amplifiers before an impedance transformation circuit, the Doherty power amplifier combines the outputs after an impedance transformation circuit in the peaking amplifier output path. This eliminates, or at least reduces, a possible impedance step down and corresponding impedance step up for the main output path. Reduction or elimination of such a step down and step up reduces insertion loss and allows increased efficiency at the first efficiency peak, as well as improving the fractional bandwidth of the Doherty power amplifier.

The present invention provides a bandwidth-boosting phase-noise-cancellation system comprising: a main signal source, an auxiliary signal source, a signal mixer connected to the output of the main signal source and the output of the auxiliary signal source, a frequency multiplier connected to the signal mixer's output, a reference signal source connected to the input of the main signal source, and a fractional divider connected between the output of the main signal source and the input of the auxiliary signal source. The bandwidth boosting system can boost up the overall fractional tuning bandwidth from the main signal source while the main signal source can be optimized for good phase noise and low power consumption with only a narrow tuning range. Moreover, the provided phase correlation and phase noise cancellation technique can help cancel the phase noise from the main signal source and improve the system phase noise even when the desired fractional bandwidth is boosted.

Various methods and systems are provided for increasing a fractional bandwidth of an ultrasound device, for use in both low and high frequency applications. In one example, where a transducer array includes one or more transducer elements comprising a plurality of capacitive micromachined ultrasound transducers (cMUT), the fractional bandwidth may be advantageously increased by applying different bias voltages to different groupings of cMUTs within each transducer element. A ratio between the different bias voltages may be optimized to maximize the fractional bandwidth. In another example, the different bias voltages may be configured to operate a first grouping of cMUTs in a transmit mode, and a second grouping of cMUTs in a receive mode.

The invention discloses a three-path non-modulation broadband pseudo Doherty power amplifier, which belongs to the field of Doherty power amplifiers and comprises a one-to-three power divider, a phase compensation network, a main power amplifier, two paths of auxiliary power amplifiers and an output synthesis network formed by four transmission lines. The asymmetric architecture that the main power amplifier works in the class AB and the two paths of auxiliary power amplifiers work in the class C is adopted, and non-modulation synthesis is realized by utilizing a microstrip line network, so that the load impedance of the main power amplifier is kept constant in a broadband. According to the Doherty power amplifier, the problems that a traditional Doherty power amplifier is insufficient in power rollback range and narrow in working bandwidth are effectively solved, the rollback range as high as 9.5 dB and the fractional bandwidth exceeding 60% are achieved, meanwhile, a transformer difficult to integrate is abandoned, and the Doherty power amplifier has good process universality and high performance.

A broadband Doherty power amplifier is disclosed. The Doherty power amplifier includes a main power amplifier and a peak amplifier. Compared to the conventional method of combining the outputs of the main and peak amplifiers before an impedance transformation circuit, this Doherty power amplifier combines the outputs after an impedance transformation circuit in the peak amplifier output path. This eliminates or at least reduces the possible impedance step drop and corresponding impedance step rise for the main output path. This reduction or elimination of the step drop and rise reduces insertion loss and allows for increased efficiency at the first efficiency peak, thus improving the fractional bandwidth of the Doherty power amplifier.

An antenna device comprising a plurality of antennas arranged on a vehicle along a latitude direction intersecting the vehicle's direction of travel, includes: a first antenna supporting radio waves at a first frequency; and a second antenna supporting radio waves at a second frequency band whose fractional bandwidth is smaller than the fractional bandwidth of the first frequency, the second antenna being arranged on an outside relative to the first antenna in the latitude direction of the vehicle, the second antenna.

A dual-input microwave power amplifier (PA) with high-efficiency. The PA exploits the continuum of modes between the Doherty and Chireix PA mode of operation to achieve 40% fractional bandwidth while relying on the physical linear dispersion of the transmission lines of the lossless output combiner. A constant output is achieved at peak power over the entire bandwidth. The output backoff varies from 6 dB in the Doherty mode to 8 dB in the Chireix mode. The PA operates over a wider range of frequencies from 1 to 8 GHz. The dual-input PA operates in mixed-mode and thus requires variable input power drives and outphasing angle.

The present invention provides a fractional-order digital-analog hybrid fronthaul method and system, comprising: a signal processing and transmission step: at the transmitting end, splitting the wireless signal into two parts, performing different-order digital-analog hybrid modulation on the two parts, and then performing frequency division multiplexing to achieve fractional bandwidth expansion; a signal reception and processing step: at the receiving end, demodulating the two different-order digital-analog hybrid optical wireless signals to recover the wireless signal. By adopting fractional-order digital-analog hybrid modulation, the present invention overcomes the problem that conventional digital-analog hybrid modulation can only achieve integer-multiple bandwidth expansion, thereby achieving the effect of improving the flexibility of the fronthaul system.

Various methods and systems are provided for increasing the fractional bandwidth (618, 718, 518) of an ultrasound device for both low and high frequency applications. In one example, where the transducer array (300) comprises one or more transducer elements (310, 314, 352, 106, 304, 302), which comprise a plurality of capacitive micromachined ultrasonic transducers (cMUTs (251, 200, 302)), the fractional bandwidth (618, 718, 518) can be advantageously increased by applying different bias voltages to different groups of cMUTs (251, 302) within each transducer element (310, 352, 106, 304, 312). The ratio between the different bias voltages can be optimized to maximize the fractional bandwidth (618, 718, 518). In another example, the different bias voltages can be configured to operate a first packet (320) of cMUTs (251, 302) in a transmit mode and to operate a second packet (322) of cMUTs (251, 302) in a receive mode.

The invention provides a bandwidth expansion system with a phase noise elimination function, which comprises a main signal source, an auxiliary signal source, a signal mixer connected to the output of the main signal source and the output of the auxiliary signal source, a frequency multiplier connected to the output of the signal mixer, and a reference signal source connected to the input of the main signal source, and a fractional divider connected between the primary signal source output and the secondary signal source input. According to the bandwidth expansion system provided by the invention, the overall fractional tuning bandwidth can be expanded from the main signal source, and the main signal source can be optimized for phase noise cancellation and low power consumption in a narrow tuning range. In addition, the phase correlation and phase noise cancellation technology provided by the invention can help to eliminate the phase noise of the main signal source, and improve the phase noise of the system when the required fractional bandwidth is improved.

Provided is an elastic wave device capable of suppressing spurs in a Rayleigh mode without causing the value of a fractional bandwidth to be too large. An elastic wave device (1) is provided with a support substrate (3), a silicon oxide layer (4) provided on the support substrate (3), a lithium niobate layer (5) provided on the silicon oxide layer (4), and an IDT electrode (6) provided on the lithium niobate layer (5). When the wavelength defined by the electrode finger pitch of the IDT electrode (6) is lambda, the thickness of the silicon oxide layer (4) is 0 lambda or more. The thickness of the IDT electrode (6) is represented by TIDT [lambda], the density of the IDT electrode (6) is represented by [rho] [g / cm3], the duty ratio of the IDT electrode (6) is represented by duty, the cutting angle of the lithium niobate layer (5) is represented by LNcut [degree], the thickness of the lithium niobate layer (5) is represented by TLN [lambda], the thickness of the silicon oxide layer (4) is represented by TSiO2 [lambda], the fractional bandwidth in the SH mode is represented by BW [%], and the electromechanical coupling coefficient in the Rayleigh mode is represented by ksaw2 [%]. TIDT, [rho], duty, LNcut, TLN, and TSiO2 are values within the range in which BW derived from formula 1 is 12% or less and ksaw2 derived from formula 2 is 0.1% or less.

A bridge-T filter is disclosed. In one aspect, the bridge-T filter may include one or more inductors associated with acoustic resonators to assist in providing out-of-band rejection while improving fractional bandwidth of the filter. In specific aspects, the additional inductors may be placed in series or parallel to the acoustic resonators. The improved fractional bandwidth and better out-of-band rejection reduces unwanted signals and improves the user experience.

A filter device includes resonators including at least one series arm resonator and at least one parallel arm resonator. The resonators include a parallel arm resonator defining and functioning as a first resonator with a largest fractional bandwidth among the resonators, and at least one second resonator. The filter device includes an inductor connected in series to the first resonator.

An ultra-wideband dual-polarized tightly coupled bowtie antenna array for ground-based polar ice sounding radar is described. The antenna array has a very large effective aperture to increase the directivity. At the same time, it is lightweight and low profile to minimize the payload and maximize the survey range. In an implementation, the antenna array operates between 180-620 MHz with a fractional bandwidth of 3.4:1. The broadband performance benefits from the tightly coupled antenna elements. A feature of the antenna array is the planar feeding structure without balun. The antenna array element has the microstrip feeding line integrated with one arm of the bowtie antenna. The other arm is directly fed by the microstrip line. By adding a ferrite core around the coax cable for common mode suppression, the bowtie antenna element can be fed differentially without using bulky vertical feeding structure and balun.

A dual-input microwave power amplifier (PA) with high-efficiency. The PA exploits the continuum of modes between the Doherty and Chireix PA mode of operation to achieve 40% fractional bandwidth while relying on the physical linear dispersion of the transmission lines of the lossless output combiner. A constant output is achieved at peak power over the entire bandwidth. The output backoff varies from 6 dB in the Doherty mode to 8 dB in the Chireix mode. The PA operates over a wider range of frequencies from 1 to 8 GHz. The dual-input PA operates in mixed-mode and thus requires variable input power drives and outphasing angle.

A broadband Doherty power amplifier is disclosed. A Doherty power amplifier includes a main power amplifier and a peaking amplifier. In contrast to conventional approaches that combine outputs from the main and peaking amplifiers before an impedance transformation circuit, the Doherty power amplifier combines the outputs after an impedance transformation circuit in the peaking amplifier output path. This eliminates, or at least reduces, a possible impedance step down and corresponding impedance step up for the main output path. Reduction or elimination of such a step down and step up reduces insertion loss and allows increased efficiency at the first efficiency peak, as well as improving the fractional bandwidth of the Doherty power amplifier.

Various methods and systems are provided for increasing a fractional bandwidth of an ultrasound device, for use in both low and high frequency applications. In one example, where a transducer array includes one or more transducer elements comprising a plurality of capacitive micromachined ultrasound transducers (cMUT), the fractional bandwidth may be advantageously increased by applying different bias voltages to different groupings of cMUTs within each transducer element. A ratio between the different bias voltages may be optimized to maximize the fractional bandwidth. In another example, the different bias voltages may be configured to operate a first grouping of cMUTs in a transmit mode, and a second grouping of cMUTs in a receive mode.

Provided is an elastic wave device in which the fractional bandwidth in each elastic wave resonator can be easily adjusted without causing an increase in size. This elastic wave device is provided with: a piezoelectric substrate (2) including a piezoelectric layer (6) having a first main surface (6a) and a second main surface (6b) that face each other; a first IDT electrode (8A) and a second IDT electrode (8B) provided directly or indirectly on the first main surface (6a) of the piezoelectric layer (6); and a first dielectric film (7A) and a second dielectric film (7B) provided on at least one of the first main surface (6a) and the second main surface (6b) of the piezoelectric layer (6). A first elastic wave resonator (1A) is configured from a portion of the piezoelectric substrate (2) where the first IDT electrode (8A) is provided, the first IDT electrode (8A), and the first dielectric film (7A). A second elastic wave resonator (1B) is configured from a portion of the piezoelectric substrate (2) where the second IDT electrode (8B) is provided, the second IDT electrode (8B), and the second dielectric film (7B). The first dielectric film (7A) and the second dielectric film (7B) each have one of a structure containing Li and Ta and a structure containing Li and Nb, and the first dielectric film (7A) and the second dielectric film (7B) have at least any one of piezoelectricity, polarization direction, and crystal structure different from each other.