There is disclosed a multi-band reconfigurable antenna device having at least one radiating element. The radiating element is connected to a single port by way of at least first and second matching circuits arranged in parallel. A high pass filter is provided between the first matching circuit and the radiating element so as to allow passage of a first, higher frequency RF signal through the first matching circuit. A low pass filter is provided between the second matching circuit and the at least one radiating element so as to allow passage of a second, lower frequency RF signal through the second matching circuit. The high pass filter blocks passage of the second, lower frequency RF signal through the first matching circuit, and the low pass filter blocks passage of the first, higher frequency RF signal through the second matching circuit. The first and second matching circuits are adjustable independently of each other so as to allow the first and second RF signals to be tuned independently of each other.

The present invention provides filter assemblies, tuning elements and a method of tuning a filter. A filter assembly includes a housing having a top cover, a bottom cover and at least one sidewall, the top cover, the bottom cover and the at least one sidewall defining an internal cavity, the housing configured to receive first through third radio frequency (RF) transmission lines; a top metal sheet mounted within the internal cavity that has a plurality of openings that form a first hole pattern; and a bottom metal sheet mounted within the internal cavity that has a plurality of openings that form a second hole pattern. The top and bottom metal sheets are vertically spaced-apart from each other in a vertically stacked relationship within the internal cavity. The top metal sheet and the bottom metal sheet each include at least one resonator.

A filter device includes a stack body, plate electrodes, resonators, and shield conductors. The plate electrodes are disposed inside the stack body apart from each other in the stacking direction. The resonators are disposed between the plate electrodes and extend in the Y-axis direction. The shield conductors are disposed on the side surfaces of the stack body, respectively. The shield conductors are connected to the plate electrodes. The resonators are disposed inside the stack body side by side in the X-axis direction. A first end of each of the resonators is connected to the shield conductor, and a second end thereof is separated from the shield conductor. The first end of each of the resonators is formed with a cutout.

A high-frequency filter includes a first terminal, a second terminal, a third terminal, a first inductor, a second inductor, a third inductor, and a fourth inductor. The first inductor and the second inductor are connected in series to each other between the first terminal and the second terminal. The third inductor and the fourth inductor are connected in parallel to each other between the third terminal and a node of the first inductor and the second inductor. The connection between the first inductor and the second inductor is an additive polarity connection. The connection between the third inductor and the fourth inductor is an additive polarity connection.

A coplanar waveguide may include a first transmission line extending between a first ground plane and a second ground plane at a first interconnect level. The coplanar waveguide may further include a shielding layer at a second interconnect level. The shielding layer may include a first set of conductive fingers coupled to the first ground plane. The first set of conductive fingers may be interdigitated with a second set of conductive fingers that are coupled to the second ground plane. Only a dielectric layer may be between the first set of conductive interdigitated fingers and the second set of conductive interdigitated fingers. The first ground plane, the second ground plane, the dielectric layer, and the shielding layer may form a capacitor.

A band pass filter includes filter circuits, first and second intermediate circuits, and a first capacitor. The first intermediate circuit includes an inductor connected between second and third capacitors. The second intermediate circuit includes an inductor connected between third and fourth capacitors. Resonant circuits included in the filter circuit are connected to ground via a common capacitor. Resonant circuits included in the filter circuit are connected to the ground via a common capacitor. The first capacitor is connected between the first and second intermediate circuits.

Low temperature co-fired ceramic (LTCC)-coupled stripline resonator filters for use as bandpass filters are implemented with combline topology or with interdigital topology. The filter bandwidths range from about 0.3 GHz to less than 1 GHz with frequency operation of about 0.1 GHz to 100 GHz. The filters have vias between adjacent resonators with via spacing significantly smaller than the wavelength at the filter center frequency to generate electrical walls between adjacent resonators resulting in coupling reduction for narrowband filter implementation. A narrowband filter transformer loading structure launches the input and the output to the first and last resonators.

An impedance conversion circuit includes an auto-transformer circuit including a first inductor connected between a first port connected on a power supply portion side and a second port connected on an antenna side and a second inductor connected between a third port that is grounded and the second port; a first phase shifter with a first end connected to the first port; an inductor connected in series between a second end of the first phase shifter and the power supply portion; and a capacitor connected in series to the inductor and connected in series between the second end of the first phase shifter and the power supply portion.

A band-pass filter includes five resonators. The five resonators are configured so that capacitive coupling is established between every two of the resonators adjacent to each other in circuit configuration. The first stage resonator and the fifth stage resonator are magnetically coupled to each other. The second stage resonator and the fourth stage resonator are capacitively coupled to each other. Each of the five resonators includes a resonator conductor portion. The respective resonator conductor portions of the first and fifth stage resonators are physically adjacent to each other. The respective resonator conductor portions of the second and fourth stage resonators are physically adjacent to each other. The respective resonator conductor portions of the first and second stage resonators are physically adjacent to each other. The respective resonator conductor portions of the fourth and fifth stage resonators are physically adjacent to each other.

A band-pass filter includes a main body, five resonators, a shield, and a partition. The main body is formed of a dielectric. The partition is formed of a conductor. The five resonators are configured so that capacitive coupling is established between every two of the resonators adjacent to each other in circuit configuration. Each of the five resonators includes a resonator conductor portion. A first stage resonator and a fifth stage resonator are magnetically coupled to each other although not adjacent to each other in circuit configuration. The partition extends to pass between the respective resonator conductor portions of the first stage resonator and the fifth stage resonator, and is electrically connected to the shield.