Abstract: An image capturing system includes six lens elements which are, in order from an object side to an image side along an optical path: a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element. Each of the six lens elements has an object-side surface facing toward the object side and an image-side surface facing toward the image side. The fourth lens element has positive refractive power, the object-side surface of the fourth lens element is concave in a paraxial region thereof, and the image-side surface of the fourth lens element is convex in a paraxial region thereof. At least one of the object-side surface and the image-side surface of at least one lens element of the image capturing system has at least one inflection point in an off-axis region thereof.

Abstract: An imaging lens assembly includes three lens elements which are, in order from an object side to an image side along an optical path: a first lens element, a second lens element and a third lens element. Each of the three lens elements has an object-side surface facing toward the object side and an image-side surface facing toward the image side. The object-side surface of the second lens element is concave in a paraxial region thereof. At least one surface of at least one lens element in the imaging lens assembly has at least one inflection point.

Abstract: An optical imaging system includes four lens elements which are, in order from an object side to an image side: a first lens element, a second lens element, a third lens element and a fourth lens element. Each of the four lens elements of the optical imaging system has an object-side surface facing toward the object side and an image-side surface facing toward the image side. The object-side surface of the first lens element is concave in a paraxial region thereof, and the image-side surface of the first lens element is convex in a paraxial region thereof. The object-side surface of the fourth lens element is convex in a paraxial region thereof, the image-side surface of the fourth lens element is concave in a paraxial region thereof, and the image-side surface of the fourth lens element has at least one convex shape in an off-axis region thereof.

Abstract: Apparatus and methods for power amplifier output matching is disclosed. In one aspect, there is provided an output matching circuit including an input configured to receive an amplified radio frequency signal from a power amplifier, a first output, and a second output. The output matching circuit further includes a first matching circuit electrically connected between the input of the output matching circuit and the first output, the first matching circuit configured to suppress harmonics of a fundamental frequency of the amplified radio frequency signal when the amplified radio frequency signal is within a first band. The output matching circuit further includes a second matching circuit electrically connected between the input of the output matching circuit and the second output, the second matching circuit configured to suppress harmonics of the fundamental frequency of the amplified radio frequency signal when the amplified radio frequency signal is within a second band different from the first band.

Abstract: An optical photographing lens assembly includes seven lens elements which are, in order from an object side to an image side along an optical path, a first lens element through a seventh lens element. Each of the seven lens elements has an object-side surface facing toward the object side and an image-side surface facing toward the image side. The object-side surface of the second lens element is convex in a paraxial region thereof. The sixth lens element has positive refractive power. The object-side surface of the seventh lens element is convex in a paraxial region thereof. At least one of the object-side surface and the image-side surface of at least one of the seven lens elements has at least one inflection point in an off-axis region thereof.

Abstract: An optical imaging system includes four lens elements which are, in order from an object side to an image side: a first lens element, a second lens element, a third lens element and a fourth lens element. Each of the four lens elements of the optical imaging system has an object-side surface facing toward the object side and an image-side surface facing toward the image side. The object-side surface of the first lens element is concave in a paraxial region thereof, and the image-side surface of the first lens element is convex in a paraxial region thereof. The object-side surface of the fourth lens element is convex in a paraxial region thereof, the image-side surface of the fourth lens element is concave in a paraxial region thereof, and the image-side surface of the fourth lens element has at least one convex shape in an off-axis region thereof.

Abstract: An imaging system lens assembly includes eight lens elements which are, in order from an object side to an image side along an optical path, a first lens element through an eighth lens element. The first lens element has negative refractive power. The object-side surface of the first lens element is concave in a paraxial region thereof and has at least one inflection point in an off-axis region thereof. The eighth lens element has positive refractive power. The object-side surface of the eighth lens element is convex in a paraxial region thereof. The image-side surface of the eighth lens element is concave in a paraxial region thereof and has at least one inflection point in an off-axis region thereof. At least one of the lens surface of at least one of the second through seventh lens elements has at least one inflection point in an off-axis region thereof.

Abstract: An optical image capturing lens assembly includes five lens elements, the five lens elements being, in order from an object side to an image side along an optical path, a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element, each of the five lens elements has an object-side surface towards the object side and an image-side surface towards the image side. The first lens element has negative refractive power. The second lens element has the image-side surface being concave in a paraxial region thereof. The third lens element with positive refractive power has the image-side surface being convex in a paraxial region thereof. The fifth lens element has the object-side surface being convex in a paraxial region thereof and the image-side surface being concave in a paraxial region thereof.

Abstract: Apparatus and methods for power amplifier output matching is disclosed. In one aspect, there is provided an output matching circuit including an input configured to receive an amplified radio frequency signal from a power amplifier, a first output, and a second output. The output matching circuit further includes a first matching circuit electrically connected between the input of the output matching circuit and the first output, the first matching circuit configured to suppress harmonics of a fundamental frequency of the amplified radio frequency signal when the amplified radio frequency signal is within a first band. The output matching circuit further includes a second matching circuit electrically connected between the input of the output matching circuit and the second output, the second matching circuit configured to suppress harmonics of the fundamental frequency of the amplified radio frequency signal when the amplified radio frequency signal is within a second band different from the first band.

Abstract: An imaging lens assembly includes six lens elements which are, in order from an object side to an image side along an optical path: a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element. Each of the six lens elements has an object-side surface facing toward the object side and an image-side surface facing toward the image side. The first lens element has positive refractive power. The image-side surface of the fourth lens element is convex in a paraxial region thereof. At least one of the object-side surface and the image-side surface of at least one lens element of the imaging lens assembly has at least one critical point in an off-axis region thereof.

Abstract: A photographing optical lens assembly includes five lens elements which are, in order from an object side to an image side along an optical path: a first lens element, a second lens element, a third lens element, a fourth lens element and a fifth lens element. The first lens element has positive refractive power. The second lens element has negative refractive power. When specific conditions are satisfied, the requirements of compact size and high image quality can be met by the photographing optical lens assembly, simultaneously.

Abstract: An imaging system lens assembly includes six lens elements which are, in order from an object side to an image side along an optical path: a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element. Each of the six lens elements has an object-side surface facing toward the object side and an image-side surface facing toward the image side. The first lens element has positive refractive power. The image-side surface of the fifth lens element is convex in a paraxial region thereof. The image-side surface of the sixth lens element is concave in a paraxial region thereof, and the image-side surface of the sixth lens element has at least one inflection point.

Abstract: An optical imaging system includes four lens elements which are, in order from an object side to an image side: a first lens element, a second lens element, a third lens element and a fourth lens element. Each of the four lens elements of the optical imaging system has an object-side surface facing toward the object side and an image-side surface facing toward the image side. The object-side surface of the first lens element is concave in a paraxial region thereof, and the image-side surface of the first lens element is convex in a paraxial region thereof. The object-side surface of the fourth lens element is convex in a paraxial region thereof, the image-side surface of the fourth lens element is concave in a paraxial region thereof, and the image-side surface of the fourth lens element has at least one convex shape in an off-axis region thereof.

Abstract: An imaging optical lens system includes a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element, a seventh lens element and an eighth lens element, in order from an object side to an image side along an optical path. The first lens element has an object-side surface being concave in a paraxial region thereof. The fourth lens element has negative refractive power. The fifth lens element has positive refractive power. At least one lens surface of at least one lens element of the imaging optical lens system has at least one critical point in an off-axis region thereof.

Abstract: An imaging system lens assembly includes a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element in order from an object side to an image side along an optical path. Each of the six lens elements has an object-side surface facing toward the object side and an image-side surface facing toward the image side. The first lens element has positive refractive power. The fifth lens element has positive refractive power. The image-side surface of the fifth lens element is concave in a paraxial region thereof. The image-side surface of the sixth lens element has at least one inflection point. A central thickness of the first lens element is a maximum among central thicknesses of all lens elements of the imaging system lens assembly.

Abstract: According to at least one aspect of the disclosure, a front-end module is provided comprising an input configured to receive a radio-frequency signal, an output configured to be coupled to an antenna, a balun coupled to the output, one or more power amplifiers coupled to the input, and an inverter coupled between the one or more power amplifiers and the balun, the inverter being configured to provide output impedance matching to the one or more power amplifiers.

Abstract: An optical imaging lens system includes a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element and a sixth lens element in order from an object side to an image side along an optical path. The first lens element has positive refractive power. The second lens element with positive refractive power has an image-side surface being convex in a paraxial region thereof. The fourth lens element has an object-side surface being concave in a paraxial region thereof and an image-side surface being convex in a paraxial region thereof. The fifth lens element has an image-side surface being convex in a paraxial region thereof. The sixth lens element with negative refractive power has an object-side surface being convex in a paraxial region thereof and an image-side surface being concave in a paraxial region thereof and having an inflection point.

Abstract: Apparatus and methods for power amplifier systems with balun and shunt capacitor are disclosed. In certain embodiments, a front-end system includes a shunt capacitor, a balun having an input side and an output side, and power amplifier stages that operate in parallel with one another to amplify a radio frequency input signal. The power amplifier stages include a first power amplifier stage having a first output coupled to the shunt capacitor and to a first input terminal on the input side of the balun, and a second power amplifier stage having a second output coupled to a second input terminal on the input side of the balun.

Abstract: An optical imaging system includes four lens elements which are, in order from an object side to an image side: a first lens element, a second lens element, a third lens element and a fourth lens element. Each of the four lens elements of the optical imaging system has an object-side surface facing toward the object side and an image-side surface facing toward the image side. The object-side surface of the first lens element is concave in a paraxial region thereof, and the image-side surface of the first lens element is convex in a paraxial region thereof. The object-side surface of the fourth lens element is convex in a paraxial region thereof, the image-side surface of the fourth lens element is concave in a paraxial region thereof, and the image-side surface of the fourth lens element has at least one convex shape in an off-axis region thereof.

Abstract: Apparatus and methods for power amplifiers with broadband matching networks are disclosed. In certain embodiments, a mobile device includes a transceiver that generates a radio frequency input signal, and a front-end system including a compound semiconductor die and a silicon switch die. The compound semiconductor die includes a power amplifier including one or more power amplifier stages that amplify the radio frequency input signal to generate a radio frequency output signal. The silicon switch die includes a band selection switch that receives the radio frequency output signal. The compound semiconductor die and the silicon switch die each include at least one controllable impedance for providing a bandwidth adjustment to the power amplifier.