

This compounds the reflection compensation problem in that the reflection compensation elements will not compensate as well, and worsen the frequency response further. Some applications require that the high pass and low pass legs be designed with differing topologies, orders and/or attenuation requirements.
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The reflection compensation elements are computed using algorithms based on identical diplexer high pass and low pass leg topologies, orders, pass band attenuation, and stop band attenuation. This is, of course, an unacceptable solution that can be resolved with the advanced design techniques presented in this article. In some cases, it may come down to a choice between meeting the physical design requirements or meeting the electrical design requirements. Adjusting for elements of more desired values can bring the elements sizes back inside the physical design requirements, and if the designer is lucky, may still meet electrical design requirements. The frequency response mitigating effect of noncontiguous diplexer design reflection compensators can be offset by element values that exceed the desired range, or whose physical size may be outside the physical design requirements. Duplexers and N-plexers with outer bandpass legs exhibit similar frequency response degradation at the outer bandpass cutoff frequencies and can be compensated for in a similar manner at the outer edge frequencies. Noncontiguous diplexers (those with frequency gaps between adjacent passbands) exhibit worse frequency response degradation but can be mitigated with the use of shunt LC-series resonator reflection compensators that force the undesired reflections into the frequency gap between the passbands and away from the passband frequencies. Ideal contiguous diplexers (those with no 3-dB frequency gaps between adjacent passbands) tend to interact right between the legs so as to mitigate, but not eliminate, undesired frequency input reflections and output responses. Undesired input reflections (S11) and droopy output frequency responses (S1,2, S1,3, …S1,N) at cutoff frequencies become difficult to manage. Duplexers (two bandpass legs), triplexers (low-pass, bandpass, and high-pass legs), and N-plexers (multiple legs), are similarly problematic for the same fundamental reasons. Ideal diplexer designs are inherently problematic even at low frequencies due to the finite source resistance and interactions of the low-pass and high-pass legs. The AXIEM planar or Analyst™ 3D finite-element method (FEM) electromagnetic (EM) simulators can be used for further analysis/optimization of multi-GHz designs.
Plexers auxl software#
N-plexer designs can be derived in Microwave Office software from duplexer and triplexer building blocks using simple copy/paste functions.

Seasoned design engineers can generally meet the device requirements with ease using this accurate and efficient software design flow that quickly achieves high-frequency diplexer, duplexer, and triplexer designs that meet both the electrical and physical design requirements. This flow has been shown to overcome numerous physical/electrical design challenges of these devices at high frequencies.ĭesign success is accomplished using the optimization capabilities in Microwave Office software, combined with the extremely accurate and flexible vendor component models available from Modelithics, and the efficient, user-friendly design automation from Nuhertz. This article presents an accurate and efficient flow for the design of these components employing a combination of Nuhertz Technologies filter solutions (FS), NI AWR software, specifically Microwave Office circuit design software, and Modelithics RF and microwave simulation models. This is especially true at high frequencies, typically above ~100MHz and into the multi GHz range, where substrate and interconnect parasitic effects can significantly degrade performance and must be optimized without overburdening the designer or lengthening development time. Diplexer, duplexer, triplexer, and N-plexer designs may include electrical and physical design requirements that are not only difficult and cumbersome, but at times may seem to be mutually exclusive.
