Abstract: An end-fire antenna for wideband low form factor applications includes a first metal layer, a second metal layer, and a dielectric layer disposed between the first and second metal layers. An open cavity formed in the dielectric layer that is filled with air, the cavity defined by a pair of sidewalls that extend from an aperture of the cavity to a rear wall of the cavity, where the depth of the aperture is defined between the aperture and the rear wall. The cavity is formed by selecting the width of the aperture of the cavity and the depth of the cavity such that the antenna achieves the same gain during operation irrespective of a variation in the thickness of the antenna.

Abstract: Systems and methods for integrating injection-locked oscillators into transceiver arrays are disclosed. In one aspect, there is provided an injection-locked oscillator (ILO) distribution system including a master clock generator configured to generate a master clock signal. The ILO distribution system also includes an ILO distribution circuit including an ILO and configured to receive the master clock signal. The ILO is configured to generate a reference clock signal based on the master clock signal. The ILO distribution circuit is further configured to generate an output signal indicative of an operating frequency of the ILO. The ILO distribution system further includes an injection-locked detector (ILD) configured to receive the master clock signal and the output signal. The ILD is further configured to determine whether the ILO is in a locked state or in an unlocked state based on the master clock signal and the output signal.

Abstract: Systems and methods for integrating injection-locked oscillators into transceiver arrays are disclosed. In one aspect, there is provided an injection-locked oscillator (ILO) distribution system including a master clock generator configured to generate a master clock signal. The ILO distribution system also includes an ILO distribution circuit including an ILO and configured to receive the master clock signal. The ILO is configured to generate a reference clock signal based on the master clock signal. The ILO distribution circuit is further configured to generate an output signal indicative of an operating frequency of the ILO. The ILO distribution system further includes an injection-locked detector (ILD) configured to receive the master clock signal and the output signal. The ILD is further configured to determine whether the ILO is in a locked state or in an unlocked state based on the master clock signal and the output signal.

Abstract: A Radio Frequency (RF) circuit including a receive path, a transmit path, a switching circuit, and an output configured to receive RF signals from an antenna in a receive mode of operation, and to provide RF signals to the antenna in a transmit mode of operation. The receive path is configured to be coupled between a low-noise amplifier and the output. The switching circuit is located in the receive path and is configured, in the receive mode, to selectively couple the low-noise amplifier to the output and to pass the received RF signals from the output to the low-noise amplifier. The transmit path is configured to be coupled between a power amplifier and the output, to provide, in the transmit mode, signals from the power amplifier to the output, bypassing the switching circuit, and to have, in receive mode of operation, an off-state impedance of at least 200+j*13 Ohm.

Abstract: An end-fire antenna for wideband low form factor applications includes a first metal layer, a second metal layer, and a dielectric layer disposed between the first and second metal layers. An open cavity formed in the dielectric layer that is filled with air, the cavity defined by a pair of sidewalls that extend from an aperture of the cavity to a rear wall of the cavity, where the depth of the aperture is defined between the aperture and the rear wall. The cavity is formed by selecting the width of the aperture of the cavity and the depth of the cavity such that the antenna achieves the same gain during operation irrespective of a variation in the thickness of the antenna.

Abstract: Apparatus and methods for true power detection are provided herein. In certain embodiments, a power amplifier system includes an antenna, a directional coupler, and a power amplifier electrically connected to the antenna by way of a through line of the directional coupler. The power amplifier system further includes a combiner that combines a first coupled signal from a first end of the directional coupler's coupled line with a second coupled signal from a second end of the directional coupler's coupled line.

Abstract: A Radio Frequency (RF) circuit including a receive path, a transmit path, a switching circuit, and an output configured to receive RF signals from an antenna in a receive mode of operation, and to provide RF signals to the antenna in a transmit mode of operation. The receive path is configured to be coupled between a low-noise amplifier and the output. The switching circuit is located in the receive path and is configured, in the receive mode, to selectively couple the low-noise amplifier to the output and to pass the received RF signals from the output to the low-noise amplifier. The transmit path is configured to be coupled between a power amplifier and the output, to provide, in the transmit mode, signals from the power amplifier to the output, bypassing the switching circuit, and to have, in receive mode of operation, an off-state impedance of at least 200+j*13 Ohm.

Abstract: Apparatus and methods for power amplifiers isolated by differential ground are provided. In certain implementations, a mobile device includes a transceiver that generates a plurality of radio frequency input signals including a first radio frequency input signal and a second radio frequency input signal, and a plurality of differential power amplifiers including a first differential power amplifier that provides amplification to the first radio frequency input signal and a second differential power amplifier that provides amplification to the second radio frequency input signal. The first differential power amplifier and the second differential power amplifier each operate with differential ground so as to provide isolation between the first differential power amplifier and the second differential power amplifier.

Abstract: Systems and methods for integrating injection-locked oscillators into transceiver arrays are disclosed. In one aspect, there is provided an injection-locked oscillator (ILO) distribution system including a master clock generator configured to generate a master clock signal. The ILO distribution system also includes an ILO distribution circuit including an ILO and configured to receive the master clock signal. The ILO is configured to generate a reference clock signal based on the master clock signal. The ILO distribution circuit is further configured to generate an output signal indicative of an operating frequency of the ILO. The ILO distribution system further includes an injection-locked detector (ILD) configured to receive the master clock signal and the output signal. The ILD is further configured to determine whether the ILO is in a locked state or in an unlocked state based on the master clock signal and the output signal.

Abstract: Systems and methods for integrating injection-locked oscillators into transceiver arrays are disclosed. In one aspect, there is provided an injection-locked oscillator (ILO) distribution system including a master clock generator configured to generate a master clock signal. The ILO distribution system also includes an ILO distribution circuit including an ILO and configured to receive the master clock signal. The ILO is configured to generate a reference clock signal based on the master clock signal. The ILO distribution circuit is further configured to generate an output signal indicative of an operating frequency of the ILO. The ILO distribution system further includes an injection-locked detector (ILD) configured to receive the master clock signal and the output signal. The ILD is further configured to determine whether the ILO is in a locked state or in an unlocked state based on the master clock signal and the output signal.

Abstract: An end-fire antenna for wideband low form factor applications includes a first metal layer, a second metal layer, and a dielectric layer disposed between the first and second metal layers. An open cavity formed in the dielectric layer that is filled with air, the cavity defined by a pair of sidewalls that extend from an aperture of the cavity to a rear wall of the cavity, where the depth of the aperture is defined between the aperture and the rear wall. The cavity is formed by selecting the width of the aperture of the cavity and the depth of the cavity such that the antenna achieves the same gain during operation irrespective of a variation in the thickness of the antenna.

Abstract: An antenna for radio-frequency electronics can include an end-fire antenna and a planar antenna spaced from the end-fire antenna for diversity of direction and antenna coverage. The end-fire antenna can be for wideband low form factor applications and have a first metal layer, a second metal layer, and a dielectric layer between the first and second metal layers. An open cavity formed in the dielectric layer that is filled with air, the cavity defined by a pair of sidewalls that extend from an aperture of the cavity to a rear wall of the cavity, where the depth of the aperture is defined between the aperture and the rear wall. The cavity is formed by selecting the width of the aperture of the cavity and the depth of the cavity such that the antenna achieves the same gain during operation irrespective of a variation in the thickness of the antenna.

Abstract: An end-fire antenna for wideband low form factor applications includes a first metal layer, a second metal layer, and a dielectric layer disposed between the first and second metal layers. An open cavity formed in the dielectric layer that is filled with air, the cavity defined by a pair of sidewalls that extend from an aperture of the cavity to a rear wall of the cavity, where the depth of the aperture is defined between the aperture and the rear wall. The cavity is formed by selecting the width of the aperture of the cavity and the depth of the cavity such that the antenna achieves the same gain during operation irrespective of a variation in the thickness of the antenna.

Abstract: Apparatus and methods for power amplifiers isolated by differential ground are provided. In certain implementations, a mobile device includes a transceiver that generates a plurality of radio frequency input signals including a first radio frequency input signal and a second radio frequency input signal, and a plurality of differential power amplifiers including a first differential power amplifier that provides amplification to the first radio frequency input signal and a second differential power amplifier that provides amplification to the second radio frequency input signal. The first differential power amplifier and the second differential power amplifier each operate with differential ground so as to provide isolation between the first differential power amplifier and the second differential power amplifier.

Abstract: Apparatus and methods for power amplifier systems with differential ground are provided. In certain implementations, a semiconductor die for a radio frequency communication system includes a differential ground network configured to distribute a ground voltage. The differential ground network is substantially symmetric with respect to a line of symmetry. The semiconductor die further includes a first differential power amplifier including a first half circuit and a second half circuit that operate differentially to provide amplification. The first half circuit and the second half circuit are symmetrically connected to the differential ground network. The semiconductor die can further include a second differential power amplifier, and the differential ground network serves to provide isolation between the first differential power amplifier and the second differential power amplifier.

Abstract: An antenna structure can include a printed circuit board module and a mold compound disposed on a side of the printed circuit board module. A planar antenna is defined by a conformal shield layer disposed on a first surface of the mold compound such that the mold compound is disposed between the printed circuit board module and the conformal shield layer. The mold compound has a cavity defined therein between the planar antenna and the printed circuit board module, the cavity filled with a material different than the mold compound material. Optionally, the cavity can be filled with air. The thickness of the mold compound layer and the shape of the conformal shield layer can be varied to optimize a performance of the antenna.

Abstract: A method for manufacturing a package with a conformal shield antenna includes forming a mold compound layer, attaching the mold compound layer to a printed circuit board, applying a conformal shield layer on a first surface of the mold compound layer, the mold compound layer disposed between the conformal shield layer and the printed circuit board module, and shaping the conformal shield layer to define a planar antenna structure. Optionally, the method includes forming a cavity in the mold compound layer, applying a cover layer over the cavity to enclose the cavity and hardening the cover layer.

Abstract: An antenna structure can include a printed circuit board module and a mold compound disposed on a side of the printed circuit board module. A planar antenna is defined by a conformal shield layer disposed on a first surface of the mold compound such that the mold compound is disposed between the printed circuit board module and the conformal shield layer. The thickness of the mold compound layer and the shape of the conformal shield layer can be varied to optimize a performance of the antenna.

Abstract: A method for reducing the jitter introduced into a digital signal by a non-linear processing element involves applying an input word representing the digital signal to a first signal path comprising a first non-linear processing element, and a complementary version of the input word to a second signal path comprising a second non-linear processing element. A common mode dither signal is injected into each signal path upstream of the non-linear processing elements. The outputs of the non-linear processing elements are combined to produce a common output with the common mode dither signal removed.

Abstract: Apparatus and methods for power amplifier systems with differential ground are provided. In certain implementations, a semiconductor die for a radio frequency communication system includes a differential ground network configured to distribute a ground voltage. The differential ground network is substantially symmetric with respect to a line of symmetry. The semiconductor die further includes a first differential power amplifier including a first half circuit and a second half circuit that operate differentially to provide amplification. The first half circuit and the second half circuit are symmetrically connected to the differential ground network. The semiconductor die can further include a second differential power amplifier, and the differential ground network serves to provide isolation between the first differential power amplifier and the second differential power amplifier.