Abstract: A resonator assembly comprising a resonant member within a conductive resonator cavity is disclosed. The resonant member extends from a first inner surface of the resonator cavity towards an opposing second inner surface. A main portion of the resonant member has a substantially constant first cross sectional area. A cap portion of the resonant member extending from the main portion towards the opposing second inner surface has a progressively increasing cross sectional area increasing from the first cross sectional area adjacent to the main portion to a larger cap cross sectional area at an end of the resonant member, the larger cap cross sectional area being at least 1.i times as large as the first cross sectional area. The resonant member may also have a flared section at the other end giving the resonant member an hour glass type shape.

Abstract: A phase shifting device is disclosed. The phase shifting device comprises an input operable to receive an input signal to be adjusted; a coupling device coupled with the input and with an output; and at least one lumped equivalent impedance transformer circuit coupled with the coupling device to receive the input signal, the lumped equivalent impedance transformer circuit having liquid crystal variable capacitors operable to adjust the input signal in response to a bias voltage applied thereto and to provide the adjusted input signal to the coupling device as an output signal. Rather than using a microstrip structure, a lumped element equivalent is instead used, which makes it possible to exploit the advantages of a liquid crystal structure but in a more compact form.

Abstract: We disclose an electrically controllable RF-circuit element that includes an electrochromic material. In an example embodiment, the electrically controllable RF-circuit element is configured to operate as a phase shifter whose phase-shifting characteristics can be changed using a dc-bias voltage applied to a multilayered structure containing a layer of the electrochromic material.

Abstract: A disclosed electrical cell enables experimental measurements of dielectric properties of an electrochromic material in the radio-frequency range of the electromagnetic spectrum. In an example embodiment, the electrical cell includes a layer of the electrochromic material under test that is sandwiched between a conducting base plane and a microstrip line. The conducting base plane and the microstrip line are electrically connected to a co-planar waveguide configured for application of superimposed DC-bias and RF-probe signals using a conventional probe station and a vector network analyzer. The S-parameters of the electrical cell measured in this manner can then be used, e.g., to obtain the complex dielectric constant of the electrochromic material under test as a function of frequency.

Abstract: A filter assembly is provided comprising a first filter (12), a notch filter (26, 26?), and a phase-shifter (36). The first filter has a stop-band. The filter assembly is configured to, in use, split the output of the first filter into a main signal on a first path (18, 20, 22) and a secondary signal on a parallel path (26, 36, 38), and to pass the signal on the parallel path through the notch filter (26) having a stop-band corresponding to the pass-band of the first filter and, or including, through the phase-shifter (36) so as to be phase-shifted at least substantially into anti-phase to the main signal to provide an adjustment signal ?f(?). The filter assembly is further configured to combine (22) the adjustment signal with the main signal so as to provide the main signal attenuated in the stop-band.

Abstract: A method, a network access node and a computer program product are disclosed. The method of estimating a distance between at least one network access node and a network node of a wireless communications network, comprises: measuring total path losses between the at least one network access node and the network node on at least two different frequencies; determining frequency-dependent path losses of transmissions by the at least one network access node on the at least two different frequencies; and estimating a distance between the network node and the at least one network access node using the total path losses and the frequency-dependent path losses on the at least two different frequencies. By measuring the total path losses between network nodes on different frequencies and using frequency-dependent path losses determined for those frequencies, it is possible to estimate the distance between network nodes.

Abstract: A method is provided of a sensor sensing a mobile user terminal for cellular radio telecommunications, the user terminal being associated with any one of a plurality of networks, each network having a distinct carrier frequency band for radio signals. The method comprises: broadcasting a common signal at each of multiple carrier frequency bands; the user terminal receiving the signal in the associated carrier frequency band of its network; the user terminal checking information in the received signal, and upon determining that the information is acceptable to allow connection to the sensor, the user terminal acknowledging to the sensor its receipt of the signal.

Abstract: A phase shifting device is disclosed. The phase shifting device comprises an input operable to receive an input signal to be adjusted; a coupling device coupled with the input and with an output; and at least one lumped equivalent impedance transformer circuit coupled with the coupling device to receive the input signal, the lumped equivalent impedance transformer circuit having liquid crystal variable capacitors operable to adjust the input signal in response to a bias voltage applied thereto and to provide the adjusted input signal to the coupling device as an output signal. Rather than using a microstrip structure, a lumped element equivalent is instead used, which makes it possible to exploit the advantages of a liquid crystal structure but in a more compact form.