1 introduction. Ammunition Delivery System

Advanced Design System (ADS) is an EDA software designed and developed by Agilent Technology Co., Ltd. (Agilent) in order to adapt to the competitive situation and conduct product development and production efficiently. Software quickly became the leader of EDA software in industrial design field. Because of its powerful function, rich template support and efficient and accurate simulation ability (especially in the field of RF microwave), it has been supported by the majority of IC designers. ADS is an industry leader in the field of high frequency design. It supports system and RF designers to develop various types of RF designs, from the simple to the most complex, from RF/ microwave modules to communication and aerospace/national defense MMIC. ADS allows designers to fully characterize and optimize the design through a full set of simulation technologies from frequency domain and time domain circuit simulation to electromagnetic field simulation. A single integrated design environment provides system and circuit simulators, as well as circuit diagram capture, layout and verification functions, so there is no need to stop and change design tools during design. Advanced design system is a powerful electronic design automation software system. It provides complete design integration for designers of cellular and portable telephones, pagers, wireless networks, radar and satellite communication systems. ADS electronic design automation function is very powerful, including time-domain circuit simulation (SPICE-like Simulation), frequency-domain circuit simulation (harmonic balance, linear analysis), three-dimensional electromagnetic simulation (EM Simulation), Communication System Simulation and digital signal processing simulation design (DSP). ADS supports RF and system design engineers to develop various RF designs, from simple to complex, from discrete RF/microwave modules to integrated MMIC for communication and aerospace/national defense. ADS is the most widely used simulation software for microwave/RF circuits and communication systems in domestic universities and research institutes. In addition, Agilent cooperated with several semiconductor manufacturers to establish ADS design kits and model files for designers to use. Users can design, plan and evaluate communication systems and design MMIC/RFIC, analog and digital circuits by using design suite and software simulation function. In addition to the above simulation design functions, ADS software also provides auxiliary design functions. For example, the Design Guide demonstrates the design process of a circuit or system through examples and explanations, while the Simulation Wizard designs and analyzes the circuit through a step-by-step interface. ADS can also provide co-simulation with other EDA software, such as SPICE, ModelSim of Mentor Graphics, NC-Verilog of Cadence, Matlab of Mathworks, etc. In addition, the rich component application model base and the connection function between measurement/verification instruments will improve the convenience, speed and accuracy of circuit and system design. ADS software versions include ADS2008, ADS2006A, ADS2005A, ADS2004A, ADS2003C, ADS2003A, ADS2002A and ADS 1.5.

2. Simulation analysis method 2. ADS software

2. 1 high frequency SPICE analysis and convolution high frequency SPICE analysis methods provide transient analysis similar to SPICE simulator, which can analyze transient effects of linear and nonlinear circuits. In SPICE simulator, frequency domain analysis models such as microstrip lines and striplines that cannot be directly used can be directly used in high-frequency SPICE simulator, because high-frequency SPICE simulator can perform transient analysis after pulling the frequency domain analysis model, and users do not need to convert the model into equivalent RLC circuit. Therefore, high frequency SPICE can not only analyze the transient response of low frequency circuits, but also analyze the transient response of high frequency circuits. In addition, high-frequency SPICE also provides the function of transient noise analysis, which can be used to simulate the transient noise of circuits, such as oscillators or phase-locked loops. Convolution analysis is an advanced time domain analysis method based on SPICE high frequency simulator. Through convolution analysis, frequency-related components, such as components defined by S parameters, transmission lines and microstrip lines, can be analyzed more accurately in time domain. 2.2 linear analysis linear analysis is a circuit simulation analysis method in frequency domain, which can be used for linear analysis of linear or nonlinear RF and microwave circuits. When conducting linear analysis, the software will first calculate the linear parameters required by each component in the circuit, such as S, Z, Y, H parameters, circuit impedance, noise, reflection coefficient, stability coefficient, gain or loss, etc. (if it is a nonlinear element, calculate the linear parameters of its working point), and then analyze and simulate the whole circuit. 2.3 Harmonic balance analysis provides a simulation method in frequency domain, steady state and large signal for circuit analysis, which can be used to analyze nonlinear circuits of multi-frequency input signals and obtain nonlinear circuit responses, such as noise, power compression point and harmonic distortion. Compared with SPICE simulation analysis in time domain, harmonic balance can provide a faster and more effective analysis method for nonlinear circuit analysis. The appearance of harmonic balance analysis method fills the shortcomings of SPICE transient response analysis method and linear S-parameter analysis method in nonlinear circuit simulation under multi-frequency input signals. Especially in today's high-frequency communication systems, most of them contain mixer circuit structure, which makes the harmonic balance analysis method more frequent and more important. In addition, for highly nonlinear circuits, such as frequency dividers in PLL, ADS also provides a simulation method of transient auxiliary HB. When analyzing the circuit, the transient analysis is carried out first, and the result of the transient analysis is used as the initial condition of harmonic balance analysis to simulate the circuit. By this method, the non-convergence situation that will occur when analyzing highly nonlinear circuits can be effectively solved. 2.4 circuit envelope circuit envelope analysis includes time domain and frequency domain analysis methods, which can be used in circuits or communication systems containing FM signals. The circuit envelope analysis draws on the advantages of SPICE and harmonic balance. The low frequency FM signal is analyzed by time domain SPICE simulation method, and the high frequency carrier signal is analyzed by frequency domain harmonic balance simulation method. 2.5 RF system analysis method provides users with the simulation and evaluation of system characteristics, in which the circuit model of the system can be verified not only by the behavior model, but also by the component circuit model. The simulation analysis of RF system includes the above linear analysis, harmonic balance analysis and circuit envelope analysis, which are used to verify the characteristics of passive components and linear system model, nonlinear system model and system with digital FM signal respectively. 2.6 Ptolemy analysis Ptolemy analysis has the ability to simulate mixed-mode systems, including digital signals, analog and high-frequency signals. ADS provides digital component models (such as FIR filter, IIR filter, AND logic gate, OR logic gate, etc.). ), communication system component model (such as QAM FM demodulator, raised cosine filter, etc. ) and analog high frequency component models (such as IQ encoder, Chebyshev filter, mixer, etc. ) use. 2.7 electromagnetic simulation analysis (Momentum) ADS software provides 2.5D planar electromagnetic simulation analysis function-Momentum (Momentum in ADS 2005a version has been upgraded to 3D electromagnetic simulator), which can be used to simulate the electromagnetic characteristics of microstrip lines, striplines and * * planar waveguides, the radiation characteristics of antennas, and the parasitic and coupling effects on circuit boards. The results of S parameters can be directly used for circuit analysis such as harmonic balance and circuit envelope, and for circuit design and verification. There are two analysis modes of momentum electromagnetic analysis: momentum microwave mode and momentum RF; Mode; Users can judge and choose to use according to the working frequency band and size of the circuit.