Abstract: An RF field effect transistor has a gate electrode, and comb shaped drain and source electrodes, fingers of the comb shaped drain being arranged to be interleaved with fingers of the source electrode, the source and drain electrodes having multiple layers (110,120,130,140). An amount of the interleaving is different in each layer, to enable optimization, particularly for low parasitic capacitance without losing all the advantage of low current density provided by the multiple layers. The interleaving is reduced for layers further from the gate electrode by having shorter fingers. The reduction in interleaving can be optimised for minimum capacitance, by a steeper reduction in interleaving, or for minimum lateral current densities in source and drain fingers, by a more gradual reduction in interleaving. This can enable operation at higher temperatures or at higher input bias currents, while still meeting the requirements of electro-migration rules.

Abstract: Consistent with an example embodiment, there is a method for calibrating an N terminal microwave measurement network. The method comprising the measurement of network parameter values of a load device depends on the knowledge of the parasitic impedance of the load device. According to the example embodiment, the accuracy of the method is improved by at least approximately determining the parasitic impedances of the load device. This may be achieved by measuring network parameter values of an auxiliary open device, having substantially identical parasitic impedance as that of the load device. The accuracy is further increased by measuring network parameter values of an auxiliary short device, having substantially identical parasitic impedance as that of the load device. A similar principle can be used for de-embedding a device under test. A load device, an auxiliary open device and an auxiliary short device each having substantially identical parasitic impedances are disclosed.

Abstract: The invention relates to a planar inductive component arranged over a substrate (103). The substrate in a first plane, a patterned ground shield (102), for shielding the winding (101) from the substrate (103). The winding (101) is at least substantially symmetrical plane. The patterned ground shield (102) comprises a plurality of electrical conductive first tracks (105) situated in a first ground shield plane in parallel with the first plane. The first tracks have an orientation perpendicular to the mirror plane (104). Without the patterned ground shield (102) the winding (101) is capacitively coupled to the substrate (103). The substrate resistance results in a degradation of the quality factor of the inductive component (100). The patterned ground shield (102) shields the winding (101) from the substrate (103), thereby eliminating the degrading effect of the substrate.

Abstract: The accuracy of a method for calibrating an N terminal microwave measurement network (10), the method comprising the measurement of network parameter values of a load device (43), depends on the knowledge of the parasitic impedance of the load device (43). According to the invention, the accuracy of the method is improved by at least approximately determining the parasitic impedances of the load device (43). In one embodiment this is achieved by measuring network parameter values of an auxiliary open device (44), having a substantially identical parasitic impedance as the load device (43). The accuracy is further increased by measuring network parameter values of an auxiliary short device (45), having a substantially identical parasitic impedance as the load device (43). A similar principle can be used for de-embedding a device under test. A load device (43), an auxiliary open device (44) and an auxiliary short device (45) having substantially identical parasitic impedances are disclosed.