![]() 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. 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. If one of the variables (for example, D) is also available inverted, a multiplexer with n-1 selector inputs is sufficient the data inputs are connected to 0, 1, D, or ~ D, according to the desired output for each combination of the selector inputs.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. The variables are connected to the selector inputs, and the function result, 0 or 1, for each possible combination of selector inputs is connected to the corresponding data input. Any Boolean function of n variables and one result can be implemented with a multiplexer with n selector inputs. Multiplexers can also be used as programmable logic devices, to implement Boolean functions. Output is open collector and same as input ![]() Since digital logic uses binary values, powers of 2 are used (4, 8, 16) to maximally control a number of inputs for the given number of selector inputs.įor 7400 series part numbers in the following table, "x" is the logic family. Other common sizes are 4-to-1, 8-to-1, and 16-to-1. The selection is directed by a separate set of digital inputs known as select lines. In electronics, a multiplexer (or mux spelled sometimes as multiplexor), also known as a data selector, is a device that selects between several analog or digital input signals and forwards the selected input to a single output line. Like a multiplexer, it can be equated to a controlled switch. ![]()
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