GaAs nonlinear transmission lines for picosecond pulse generation and millimeter-wave sampling

Abstract

linear regime by introduction of the large-signal capacitance, a parameter that is scarcely defined for NLTLs acting as frequency multipliers. The LSSP simulation does not require the introduction of C ls , and is able to provide the frequency response by taking the actual operating conditions (power level of feeding signals) and device nonlinearity into account. Because the filtering properties of NLTLs have a direct influence on circuit performance, the LSSP simulation approach is a powerful tool for the design of NLTL frequency multipliers. CONCLUSIONSIn this Letter, two important aspects of NLTL simulation have been considered: the degree of accuracy provided by the lumpedelement approach and the analysis of the transmission properties under large-signal conditions. It has been demonstrated that the lumped-element model can be used to study the linear and nonlinear behavior of the circuit, if the shunt capacitance dominates the per-section capacitance of the line. Large-signal S-parameter simulation has been demonstrated to be a powerful technique for the study of the filtering properties of NLTLs under nonlinear operating conditions. REFERENCES 1. R. Hirota and K. Suzuki, Theoretical and experimental studies of lattice solitons in nonlinear lumped networks, Proc IEEE 61 (1973)

Nonlinear transmission lines for pulse shaping in silicon

“…Improving the transitions by shrinking the rise and fall times of pulses can be useful in other applications, such as high-speed sampling and timing systems. Nonlinear transmission lines (NLTLs) sharpening of either the rising or falling edge of a pulse has been demonstrated on a GaAs technology [9], [10]. However, to the best of our knowledge, to this date there has been no demonstration of simultaneous reduction of both rise and fall times in an NLTL.…”

“…Defining an effective capacitance, , so that , the pulse height is given by (9) Using (9), we can relate to an effective voltage . It is straightforward to show that (10) So it is the capacitance at one-third the peak amplitude that determines the effective propagation velocity. Using (8)- (10) we can easily calculate the half-height width of the pulse to be (11) As can be seen, in a weakly dispersive and nonlinear transmission line, the nonlinearity can counteract the normally present dispersive properties of the line maintaining solitary waves that propagate without dispersion.…”

“…These solitary waves, now called solitons, have become important subjects of research in diverse fields of physics and engineering. There is a considerable body of work on solitons in applied mathematics (e.g., [2], [3]), applied physics-especially in optics (e.g., [4]- [7])-and a few works in electronics [8]- [10]. The ability of solitons to propagate with small dispersion can be used as an effective means to transmit data, modulated as short pulses over long distances; one example of this is the ultra wideband impulse radio that has recently gained popularity [16].…”

Feasibility of a low‐cost hybrid tunable phase shifter based on nonlinear transmission lines

“…Our purpose is to design hybrid voltage-variable phaseshifters. Varactor-loaded transmission lines have been used in several applications, using both nonlinear [1][2][3][4] and linear (smallsignal) [5][6][7] effects of the diodes. In some recent demonstrations [8,9], diode-loaded transmission lines have been used as delay lines in antenna applications.…”

Gas-absorption spectroscopy with electronic terahertz techniques

“…The GaAs integrated circuit (IC) NLTL's used in this study consist of series inductors (or sections of high-impedance transmission lines) with varactor diodes periodically placed as shunt elements. On this structure at room temperature, a fast ( 1-2 ps) voltage step develops from a sinusoidal input because the propagation velocity is modulated by the diode capacitance , , where is the line inductance and is the sum of the diode and parasitic line capacitance [6], [7]. Limitations of the NLTL arise from its periodic cutoff frequency, waveguide dispersion, interconnect metallization losses, and diode resistive losses.…”