Abstract: This patent describes a method and system which overcomes the LO-leakage problem during modulation and demodulation, common to direct conversion and similar RF transmitters and receivers. This problem is solved using a virtual local oscillator (VLO™) signal which emulates mixing with a local oscillators (LO) signal. The VLO signal is constructed using complementary mixing signals that suppress mixing power in the bandwidth of the input signal, and within the bandwidth of the output frequency. Specifically, mixing is done in two or more stages, using time-varying mixing signals &phgr;1 and &phgr;2 which satisfy the following criteria: &phgr;1 * &phgr;2 having significant power at the frequency of the LO being emulated, one of &phgr;1 and &phgr;2 having minimal p ower around the frequency of the output signal y(t), and the other of &phgr;1 and &phgr;2 having minimal power around the centre frequency, fRF, of the input signal x(t).

Abstract: A dual-damascene process where first alternate ILDs are made of a first material and second alternate ILDs are made of a second material. Each material is etchable at a faster rate than the other in the presence of different etchant such as for an organic polymer and an inorganic low k material. This allows the ILDs to be deposited alternately on one another without an etchant stop layer thereby reducing capacitance.

Abstract: The invention relates to a microelectronic device and a structure therein that includes a diffusion barrier layer having a first thickness and a first dielectric constant. An etch stop layer is disposed above and on the diffusion barrier layer. The etch stop layer has a second thickness and a second dielectric constant.