A differential double balanced duplexer (dDBD) includes a transmitter and a first balun are coupled to a first impedance tuner that produces a first impedance that blocks received signals at a first frequency range from travelling across the first balun and into the transmitter, and a second impedance that passes transmitted signals at a second frequency range to travel across the first balun to the antenna. The dDBD also includes a receiver and a second balun coupled to a second impedance tuner that produces a first impedance that allows the received signals at the first frequency range to travel across the second balun and into the receiver, and a second impedance that blocks the transmitted signals at the second frequency range from travelling across the second balun and into the receiver. As such, the dDBD allows for increased isolation and decreased insertion loss.

In a multilayer filter, first and second resonant circuits are arranged in a direction crossing a stacking direction of a plurality of dielectric layers. An input/output portion includes an input/output port group including an unbalanced port and a pair of balanced ports or an input/output port group including two pairs of balanced ports. The second resonant circuit includes an inductor conductor, a first capacitor conductor, and a second capacitor conductor. The inductor conductor includes first and second ends. The first capacitor conductor is connected to the first end. The second capacitor conductor is connected to the second end. The second dielectric layer has a dielectric constant lower than that of the first dielectric layer. The first and second capacitor conductors are provided in the first dielectric layer. At least a part of the inductor conductor is provided in the second dielectric layer.

An apparatus includes an RF apparatus, and a wideband multi-band matching balun. The wideband multi-band matching balun includes a multi-band balun, which includes at least one three-element frequency-dependent resonator (TEFDR). The wideband multi-band matching balun further includes a differential-to-differential matching circuit coupled to the RF apparatus. The differential-to-differential matching circuit includes at least one TEFDR.

A high-order filter with a capacitive inner tapping technique is disclosed. The filter includes an inductor and a first resonant circuit including a first portion of the inductor and a first capacitor. The first resonant circuit is configured to attenuate first frequency components of an input signal above a cutoff frequency to generate a filtered signal. The filter further includes a second resonant circuit coupled in parallel with the first resonant circuit and including the first portion of the inductor and a second capacitor. The second resonant circuit is configured to attenuate the first frequency components of the input signal to generate the filtered signal. A third resonant circuit includes a second portion of the inductor and a third capacitor, wherein the third resonant circuit is configured to attenuate second frequency components of the filtered signal above the cutoff frequency to generate an output signal.

A differential combiner circuit (200) comprises three ports each has two terminals (1a, 1b, 2a, 2b, 3a, 3b). The differential combiner circuit (200) further comprises a first sub-circuit comprising a first inductor (L1) connected between the first terminals (1a, 2a) of the first and second ports, and a first capacitor (C1) connected between the first terminals (2a, 3a) of the second and third ports; a second sub-circuit comprising a second inductor (L2) connected between the second terminals (1b, 2b) of the first and second ports, and a second capacitor (C2) connected between the second terminals (2b, 3b) of the second and third ports. The differential combiner circuit (200) further comprises a third capacitor (C3) connected between the first and second terminals (1a, 1b) of the first port, a third inductor (L3) connected between the first and second terminals (3a, 3b) of the third port; a first resistor (R1) connected between the first terminal (1a) of the first port and the second terminal (3b) of the third port; and a second resistor (R2) connected between the second terminal (1b) of the first port and the first terminal (3a) of the third port.

A dual mode notch filter for use in a multi-band millimeter wave (mmW) transmitter includes a transmit filter circuit disposed between two amplifiers in a mmW transmit signal path, the transmit filter circuit formed by at least one switch, at least one capacitor, and a double-tuned transformer, the transmit filter circuit having at least two modes configured to selectively filter a spurious signal in at least a first communication band.

An electronic device may include wireless circuitry having an LC filter. The LC filter may include first and second series inductors coupled between the input and output of the LC filter. An input capacitor can be coupled at the input of the LC filter, and an output capacitor can be coupled at the output of the LC filter. Feedforward capacitors can be cross-coupled with the first and second series inductors to at least partially or fully cancel out any parasitic capacitance associated with the first and second series inductors to mitigate any undesired self-resonant effects associated with the series inductors.

A positive electrode side input loop line (10a) and a positive electrode side output loop line (10b), and a negative electrode side input loop line (11a) and a negative electrode side output loop line (11b) form two sets of coupling loops, and the loop lines of the two sets have the same winding direction, and have the same loop sizes of and relative relationship between the loop lines. A capacitor (3) is connected in series between the positive electrode side input loop line (10a) and the negative electrode side input loop line (11a).

Techniques for a configurable analog-to-digital converter filter to ameliorate transfer function peaking or frequency response issues are provided. In an example, a front-end circuit of a processing circuit can include a resistor-capacitor filter including at least two capacitors and a switch circuit. The resistor-capacitor filter can couple an input analog signal to the processing circuit. The switch circuit can couple to a first capacitor of the at least two capacitors, and can selectively place a terminal of the first capacitor at a selected one of a plurality of distinct nodes of the resistor-capacitor filter to configure the circuit to address the peaking or frequency response issue.

Certain aspects of the present disclosure are generally directed to a structure for a balanced-unbalanced (balun) transformer. For example, certain aspects of the present disclosure provide a transformer that generally includes a first winding having a first terminal coupled to an input node and a second terminal coupled to a reference potential node. The transformer may also include a first impedance coupled between a center tap of the first winding and the reference potential node, and a second winding magnetically coupled to the first winding and having a first terminal coupled to a first differential node of a differential output pair, a second terminal coupled to a second differential node of the differential output pair, and a center tap coupled to the reference potential node.