CN101000638A - Computer aided high frequency circuit model analog analysing method and system - Google Patents

Computer aided high frequency circuit model analog analysing method and system Download PDF

Info

Publication number
CN101000638A
CN101000638A CN 200610001174 CN200610001174A CN101000638A CN 101000638 A CN101000638 A CN 101000638A CN 200610001174 CN200610001174 CN 200610001174 CN 200610001174 A CN200610001174 A CN 200610001174A CN 101000638 A CN101000638 A CN 101000638A
Authority
CN
China
Prior art keywords
circuit model
high frequency
design parameter
computer aided
circuit
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
CN 200610001174
Other languages
Chinese (zh)
Other versions
CN100461188C (en
Inventor
赖俊佑
许峰铭
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Pizhou Elson Electronic Technology Co Ltd
Original Assignee
Inventec Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Inventec Corp filed Critical Inventec Corp
Priority to CNB2006100011745A priority Critical patent/CN100461188C/en
Publication of CN101000638A publication Critical patent/CN101000638A/en
Application granted granted Critical
Publication of CN100461188C publication Critical patent/CN100461188C/en
Expired - Fee Related legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Design And Manufacture Of Integrated Circuits (AREA)
  • Management, Administration, Business Operations System, And Electronic Commerce (AREA)

Abstract

A model analog analysis system of computer auxiliary high frequency circuit comprises model defining module of pattern interface circuit, processing module of design parameter and output module of analog result. The said system is featured as enabling user to use said patternized interface to output a set of design parameter of circuit model for making said analysis system automatically calculate out operation character parameter corresponding to said set of design parameter.

Description

Computer aided high frequency circuit model analog analysing method and system
Technical field
The invention relates to a kind of area of computer aided breadboardin technology, particularly about a kind of computer aided high frequency circuit model analog analysing method and system, be applied in a computer platform, an area of computer aided circuit design workstation for example, this computer platform provides the computer aided high frequency circuit model analog analysing function, the user is when design one high-frequency transmission line (for example mobile communication high-speed digital circuit), the convenient circuit model of simulating this high-frequency transmission line apace by this computer platform that reaches is tried to achieve the characterisitic parameter of this high-frequency transmission line when practical operation.
Background technology
At present because wireless network, mobile phone and GPS (Global PositioningSystem, fast-developing and the vast demand of wireless communication technique such as GPS), the design of high-speed digital circuit and make a very popular electronic technology that has become in the electronics industry.Basically high-speed digital circuit is to arrange to go up a kind of conducting wire that is called little circuit (micro strips) that little thus circuit transmits the digital signal of ultra-high frequency, for example digital signal of 1GHz to 3GHz (gigahertz).
HSPICE is that a kind of computer assisted circuit simulation program that arrives commonly used is gone up in the high-speed digital circuit design, can simulate the operating characteristic that various high-frequency signal transmission wires road shows under various design.Yet the shortcoming of HSPICE circuit simulation program in practical application of industry use at present is, the user must write a lot of circuit model design parameter description document at first voluntarily at the design of each specific high-speed digital circuit, define the every design parameter of the designed circuit model of user whereby, for example comprise size, physical characteristics, the line-spacing of transmission line, dielectric coefficient of circuit board or the like.In addition, in the design of some high-speed digital circuit, this circuit model design parameter description document must comprise RLGC (Resistance-Inductance-Conductance-Capacitance) model on the lamination framework of circuit board again, and the foundation of this RLGC model must be write a program voluntarily by the circuit design slip-stick artist, describes the characteristic of circuit board lamination framework and the geometry and the relevant parameter and the coordinate figure of little circuit; Utilize electromagnetic field analysis device (field solver) to try to achieve suitable RLGC model at last again.Yet this process rather wastes time and energy and is easy to and makes mistakes.In addition, this common method also can't calculate rational cross-talk (cross talk) coefficient and make comparisons by the circuit design slip-stick artist, and making can the too much arrangement space of waste on the circuit layout of comparatively dense transmission line.
Summary of the invention
For overcoming the shortcoming of above-mentioned prior art, fundamental purpose of the present invention is to provide a kind of computer aided high frequency circuit model analog analysing method and system, and the circuit design slip-stick artist of high-speed digital circuit can be more convenient and be carried out sunykatuib analysis work for the circuit model of various high-speed digital circuit apace.
Computer aided high frequency circuit model analog analysing method of the present invention and system are applied in computer platform, an area of computer aided circuit design workstation for example, the computer aided high frequency circuit model analog analysing function that provides a user to control to this computer platform, the user is when design one high-frequency transmission line (for example mobile communication high-speed digital circuit), the more convenient circuit model of simulating this high-frequency transmission line apace by this computer platform that reaches is tried to achieve the characterisitic parameter of this high-frequency transmission line when practical operation.
Computer aided high frequency circuit model analog analysing method of the present invention comprises at least: show a graphical interface on this computer platform, the design parameter input function that provides a circuit model selection function that a user controls and a user to control; Wherein this circuit model selection function is to select a specific circuit model, and this design parameter input function then is the input one group design parameter relevant with this circuit model; Receive the received design parameter of this graphical interface, and responsively calculate one group of corresponding operating characteristic parameter according to one group of relevant specific operational formula of the circuit model of this group design parameter in view of the above; And the operating characteristic parameter of trying to achieve is presented on this computer platform.
On the entity framework, computer aided high frequency circuit model analog analysing of the present invention system comprises at least: (A) graphic interface formula circuit model definition module, can on this computer platform, show a graphical interface, the design parameter input function that provides a circuit model selection function that a user controls and a user to control; Wherein this circuit model selection function is to select a specific circuit model, and this design parameter input function then is the input one group design parameter relevant with this circuit model; (B) a design parameter processing module, can receive the received design parameter of this graphic interface formula circuit model definition module, and responsively calculate one group of corresponding operating characteristic parameter according to one group of relevant certain operations formula of the circuit model of this group design parameter in view of the above; And (C) analog result output module, the operating characteristic parameter that this design parameter processing module can be tried to achieve is presented on this computer platform.
Computer aided high frequency circuit model analog analysing method of the present invention and system adopt patterned interface, the user can be fully by this patterned interface output set of circuits Model Design parameter, make computer aided high frequency circuit model analog analysing of the present invention system calculate the pairing operating characteristic parameter of this group design parameter automatically.The present invention allows the circuit design slip-stick artist of high-speed digital circuit in the process of breadboardin, needn't write tediously long circuit model description document with wasting time and energy, therefore can make the design of high-speed digital circuit and simulation more quick and effective.
Description of drawings
Fig. 1 is system's basic framework synoptic diagram of the Object Oriented OO component model of computer aided high frequency circuit model analog analysing of the present invention system;
An example of Fig. 2 graphical interface that to be computer aided high frequency circuit model analog analysing of the present invention system show at computer screen.
Embodiment
Embodiment
Below be conjunction with figs., describe the embodiment of computer aided high frequency circuit model analog analysing method of the present invention and system in detail.
Fig. 1 shows the application mode of computer aided high frequency circuit model analog analysing system of the present invention (part shown in the frame of broken lines of label 100 indications) and the basic framework of Object Oriented OO component model (object-oriented component model) thereof.As shown in the figure, computer aided high frequency circuit model analog analysing of the present invention system 100 is to carry a computer platform 10 in practical application, an area of computer aided circuit design workstation for example, the computer aided high frequency circuit model analog analysing function that provides a user to control to this computer platform 10, user's (being the circuit design slip-stick artist of high-speed digital circuit) can pass through the circuit model of the various high-frequency transmission lines of these computer platform 10 simulations more convenient and apace, tries to achieve the characterisitic parameter of high-frequency transmission line when practical operation.
As shown in Figure 1, the Object Oriented OO component model (object-oriented component model) of computer aided high frequency circuit model analog analysing of the present invention system 100 entity frameworks comprises at least: (A) graphic interface formula circuit model definition module 110; (B) a design parameter processing module 120; And (C) analog result output module 130.On concrete enforcement, computer aided high frequency circuit model analog analysing of the present invention system 100 can realize with computer program fully, and this computer program for example is integrated into a circuit simulation software in add-on module (plug-in module) mode of a software, the circuit simulation software of HSPICE for example.
The individual attribute and the function of each composition module in the computer aided high frequency circuit model analog analysing of the present invention system 100 below are described respectively.
Graphic interface formula circuit model definition module 110 can show as shown in Figure 2 a graphical interface 200 on the screen 11 of this computer platform 10, the user can select required circuit model and the relevant design parameter of input.On concrete enforcement, this graphical interface 200 for example comprises circuit model option figure row 210, a circuit model viewing area 220, a design parameter input field 230 and an analog result viewing area 240; Wherein show the option figure of the specific circuit model of a cover on these circuit model option figure row 210, the user can for example utilize mouse 12 to click required circuit model; 220 of this circuit model viewing areas are the structural forms of the circuit model that shows that the user clicks; Design parameter input field 230 comprises a series of data input lattice, the user can for example use the numerical value (annotate: if the user clicks other different circuit model, then this design parameter input field 230 shows different design parameters) of the shown circuit model every design parameter structurally in this circuit model viewing area of keyboard 13 input 220; 240 display simulation results in analog result viewing area (i.e. one group of corresponding operating characteristic parameter).
In example shown in Figure 2, the circuit model that the user selects for example is the circuit model of a pair of high-frequency transmission line, and the design parameter input field 230 of therefore graphical interface 200 will be divided into 2 numerical value input fields: a geometric parameter input field 231 and a line-spacing parameter input field 232; Wherein one group of design parameter relevant with geometry forms of these geometric parameter input field 231 inputs for example comprises the first dielectric layer height H, the second dielectric layer height H 1, bottom width W, top width W2, conductor thickness T, the first planar thickness T1, second planar thickness T2 or the like; Input one group of design parameter relevant in 232 of line-spacing parameter input fields with line-spacing (just with operating characteristic in the relevant parameter of cross-talk coefficient).After the user is by one group of required design parameter of these design parameter input field 230 inputs, then be optional by simulation start key [Simulate] 250, graphic interface formula circuit model definition module 110 responsively receives the design parameter of user's input and sends a design parameter and handle active information to design parameter processing module 120.When practical operation, this graphic interface formula circuit model definition module 110 can respond 2 users and control incident: the design parameter incoming event 302 that the circuit module that the user controls selects incident 301 and user to control; Wherein the circuit module controlled of user selects incident 301 promptly not to be to use the person to utilize mouse 12 to click required circuit model from circuit model option figure row 210; 302 persons of being to use of the design parameter incoming event that the user controls utilize the numerical value of keyboard 13 input design parameters to design parameter input field 230.
Design parameter processing module 120 can respond the design parameter processing active information that above-mentioned graphic interface formula circuit model definition module 110 sends, receive one group of design parameter of user's input, and responsively calculate circuit model pairing operating characteristic parameter under the design parameter that the user sets that circuit model viewing area 220 shows according to one group of specific operational formula.For instance, as shown in Figure 2, if the circuit model that the user clicks is a pair of high-frequency transmission line, then this design parameter processing module 120 promptly can calculate this characteristic impedance to high-frequency transmission line (characteristic impedance), reverse cross-talk coefficient (backward crosstalk coefficient) and forward cross-talk coefficient (forward crosstalkcoefficient) according to the design parameter of user's input.Because these operational formulas are the breadboardin formula that adopts available circuit to learn, therefore it is not described further
The analog result (being the operating characteristic parameter) 303 that analog result output module 130 can be tried to achieve above-mentioned design parameter processing module 120 is shown to the user by the analog result viewing area 240 in this graphical interface 200.In example shown in Figure 2, if the circuit model that the user clicks is a pair of high-frequency transmission line, then the numerical value of this analog result output module 130 characteristic impedance Z 0, reverse cross-talk coefficient Kb and forward cross-talk COEFFICIENT K f that promptly design parameter processing module 120 can be tried to achieve is presented at the analog result viewing area 240 in this graphical interface 200, simultaneously, also can for example pass through another display interface display simulation result.
Below promptly utilize an example that the mode of operation of computer aided high frequency circuit model analog analysing system 100 of the present invention when practical application is described.In example, therefore suppose that user's (being the circuit design slip-stick artist) will design pair of parallel high-frequency transmission line arranged side by side, this carries out sunykatuib analysis to high-frequency transmission line at first to utilize 100 pairs of computer aided high frequency circuit model analog analysing of the present invention systems.
Please consult Fig. 1 and Fig. 2 simultaneously, computer aided high frequency circuit model analog analysing method of the present invention is when practical application, enable computer aided high frequency circuit model analog analysing of the present invention system 100 by the user, promptly graphic interface formula circuit model definition module 110 shows as shown in Figure 2 a graphical interface 200 on the screen 11 of computer platform 10.Because the circuit that the user will design is a pair of parallel high-frequency transmission line arranged side by side, therefore the user can utilize mouse 12, clicks corresponding option figure (just sending the circuit module selection incident 301 that a user controls) from the circuit model option figure row 210 of graphical interface 200.Make circuit model viewing area 220 demonstrate the pattern of the circuit model of user's selection, show one group of design parameter W1, W2, H, H1, T, T1, T2 and S relevant simultaneously with this circuit model.The user imports the numerical value (just sending the design parameter incoming event 302 that the user controls) of these design parameters by design parameter input field 230 and keyboard 13 in the graphical interface 200.After finishing the numerical value input service, the user is optional by simulation start key [Simulate] 250, graphic interface formula circuit model definition module 110 responsively receives the design parameter of user's input, and send a design parameter and handle active information to design parameter processing module 120, design parameter processing module 120 responsively receives the design parameter of user's input, and according to one group of specific relevant operational formula of circuit model that clicks with the user, calculate this circuit model pairing operating characteristic parameter under this design parameter, comprise characteristic impedance Z 0, reverse cross-talk coefficient Kb, numerical value with forward cross-talk COEFFICIENT K f.Follow the analog result (being the operating characteristic parameter) 303 that analog result output module 130 can be obtained this design parameter processing module 120, be shown to the user by the analog result viewing area 240 in this graphical interface 200.
If the dissatisfied analog result of user then can be re-entered one group of new design parameter again to design parameter input field 230, the analog result that 100 outputs one of computer aided high frequency circuit model analog analysing of the present invention system are new.Otherwise,, then can utilize this group design parameter actual design to go out a pair of high-frequency transmission line if the user pleases oneself to analog result.
Generally speaking, the invention provides a kind of computer aided high frequency circuit model analog analysing method and system, carry, the computer aided high frequency circuit model analog analysing function that provides a user to control to this computer platform to a computer platform; The present invention adopts a patterned interface, the user can be fully by this patterned interface output set of circuits Model Design parameter, computer aided high frequency circuit model analog analysing of the present invention system calculates the pairing operating characteristic parameter of this group design parameter automatically.The present invention allows the circuit design slip-stick artist of high-speed digital circuit in the process of breadboardin, needn't write tediously long circuit model description document with wasting time and energy, makes that therefore the design of high-speed digital circuit and simulation are more quick and effective.

Claims (8)

1. a computer aided high frequency circuit model analog analysing method is applied in a computer platform, the computer aided high frequency circuit model analog analysing function that provides a user to control to this computer platform; It is characterized in that this computer aided high frequency circuit model analog analysing method comprises at least:
On this computer platform, show a graphical interface, the design parameter input function that provides a circuit model selection function that a user controls and a user to control; Wherein this circuit model selection function is to select a specific circuit model, and this design parameter input function then is the input one group design parameter relevant with this circuit model;
Receive the received design parameter of this graphical interface, and responsively calculate one group of corresponding operating characteristic parameter according to one group of relevant specific operational formula of the circuit model of this group design parameter in view of the above; And
The operating characteristic parameter of trying to achieve is presented on this computer platform.
2. computer aided high frequency circuit model analog analysing method as claimed in claim 1 is characterized in that, this computer platform is an area of computer aided circuit design workstation.
3. computer aided high frequency circuit model analog analysing method as claimed in claim 1 is characterized in that, this circuit model is the circuit model of the high-frequency transmission line on the high-speed digital circuit.
4. computer aided high frequency circuit model analog analysing method as claimed in claim 1 is characterized in that, this analytical approach is to be integrated into a HSPICE circuit simulation software.
5. a computer aided high frequency circuit model analog analysing system can carry to a computer platform, the computer aided high frequency circuit model analog analysing function that this computer platform provides a user to control; It is characterized in that this computer aided high frequency circuit model analog analysing system comprises at least:
One graphic interface formula circuit model definition module can show a graphical interface on this computer platform, the design parameter input function that provides a circuit model selection function that a user controls and a user to control; Wherein this circuit model selection function is to select a specific circuit model, and this design parameter input function then is the input one group design parameter relevant with this circuit model;
One design parameter processing module, can receive the received design parameter of this graphic interface formula circuit model definition module, and responsively calculate one group of corresponding operating characteristic parameter according to one group of relevant certain operations formula of the circuit model of this group design parameter in view of the above; And
One analog result output module, the operating characteristic parameter that this design parameter processing module can be tried to achieve is presented on this computer platform.
6. computer aided high frequency circuit model analog analysing as claimed in claim 5 system is characterized in that this computer platform is an area of computer aided circuit design workstation.
7. computer aided high frequency circuit model analog analysing as claimed in claim 5 system is characterized in that this circuit model is the circuit model of the high-frequency transmission line on the high-speed digital circuit.
8. computer aided high frequency circuit model analog analysing as claimed in claim 5 system is characterized in that this system is integrated into a HSPICE circuit simulation software.
CNB2006100011745A 2006-01-13 2006-01-13 Computer aided high frequency circuit model analog analysing method and system Expired - Fee Related CN100461188C (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CNB2006100011745A CN100461188C (en) 2006-01-13 2006-01-13 Computer aided high frequency circuit model analog analysing method and system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CNB2006100011745A CN100461188C (en) 2006-01-13 2006-01-13 Computer aided high frequency circuit model analog analysing method and system

Publications (2)

Publication Number Publication Date
CN101000638A true CN101000638A (en) 2007-07-18
CN100461188C CN100461188C (en) 2009-02-11

Family

ID=38692606

Family Applications (1)

Application Number Title Priority Date Filing Date
CNB2006100011745A Expired - Fee Related CN100461188C (en) 2006-01-13 2006-01-13 Computer aided high frequency circuit model analog analysing method and system

Country Status (1)

Country Link
CN (1) CN100461188C (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102289530A (en) * 2010-06-21 2011-12-21 上海电气集团股份有限公司 Universal girder parametric computer modelling system of crane
CN102663175A (en) * 2012-03-27 2012-09-12 苏州芯禾电子科技有限公司 System and method for constructing three-dimensional model of radio-frequency passive device
CN102880735A (en) * 2011-07-13 2013-01-16 通用电气公司 Methods and systems for simulating circuit operation
CN104156510B (en) * 2014-07-24 2017-09-22 清华大学 A kind of system and method for analyzing computer hardware experiment design
CN111523285A (en) * 2020-04-26 2020-08-11 伟宸科技(武汉)有限公司 Design method of circuit for releasing ultralow frequency waves
CN117436283A (en) * 2023-12-13 2024-01-23 青岛昊宇重工有限公司 Computer aided design method, system and storage medium for chimney

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3008876B2 (en) * 1997-02-26 2000-02-14 日本電気株式会社 Simulation method for semiconductor integrated circuit
JP2000331049A (en) * 1999-05-19 2000-11-30 Mitsubishi Electric Corp High frequency circuit verification device
JP2001160084A (en) * 1999-09-22 2001-06-12 Seiko Instruments Inc Device and method for analyzing electronic circuit
JP2004139159A (en) * 2002-10-15 2004-05-13 Toshiba Tec Corp Circuit simulation device, program, and server device

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102289530A (en) * 2010-06-21 2011-12-21 上海电气集团股份有限公司 Universal girder parametric computer modelling system of crane
CN102880735A (en) * 2011-07-13 2013-01-16 通用电气公司 Methods and systems for simulating circuit operation
CN102880735B (en) * 2011-07-13 2017-04-12 通用电气公司 Systems for simulating circuit operation
CN102663175A (en) * 2012-03-27 2012-09-12 苏州芯禾电子科技有限公司 System and method for constructing three-dimensional model of radio-frequency passive device
CN104156510B (en) * 2014-07-24 2017-09-22 清华大学 A kind of system and method for analyzing computer hardware experiment design
CN111523285A (en) * 2020-04-26 2020-08-11 伟宸科技(武汉)有限公司 Design method of circuit for releasing ultralow frequency waves
CN111523285B (en) * 2020-04-26 2023-04-14 伟宸科技(武汉)有限公司 Design method of circuit for releasing ultralow frequency waves
CN117436283A (en) * 2023-12-13 2024-01-23 青岛昊宇重工有限公司 Computer aided design method, system and storage medium for chimney
CN117436283B (en) * 2023-12-13 2024-03-26 青岛昊宇重工有限公司 Computer aided design method, system and storage medium for chimney

Also Published As

Publication number Publication date
CN100461188C (en) 2009-02-11

Similar Documents

Publication Publication Date Title
CN100461188C (en) Computer aided high frequency circuit model analog analysing method and system
US8949102B2 (en) Method and system for power delivery network analysis
CN101515211B (en) Handwriting input method, device and user terminal
CN109491743A (en) Visual Report Forms generation method, device, electronic equipment and storage medium
CN105005439A (en) Icon management method and device and mobile terminal
CN105701300A (en) Spacecraft electrical information query system
CN107291582A (en) Intelligent integration method of testing based on standard big data
US20230096934A1 (en) Integrated circuit post-layout simulation method and device, electronic device and storage medium
CN103294351B (en) A kind of display packing and electronic equipment
CN107016114A (en) Drawing browsing method and device
CN104462631B (en) Circuit diagram generating device and circuit diagram generating method
CN105094355B (en) Input method and related electronic device
CN109085983A (en) Method of controlling operation thereof, device, storage medium and electronic equipment
JP2009069884A (en) Information processor, power supply system tree creation method and program
CN109377184B (en) Work order opening method, device, storage medium and terminal
CN102024071A (en) Printed circuit board wiring system and polygon merging method on printed circuit board
CN101131709B (en) Distributed circuit layout character face processing method and system thereof
KR101584635B1 (en) Method and system for making index page using content authoring tool
CN106202589A (en) A kind of house ornamentation pipeline designs method and system
CN104915132A (en) Information processing method and equipment
US20210303744A1 (en) Computer aided design (cad) model connection propagation
CN104932749B (en) A kind of Coordinate calculation method of touch point, device and touch-screen equipment
CN104156148A (en) Method and device for providing virtual keyboards for mobile equipment
CN103092425A (en) Method for achieving touch screen control through mouse man-machine interface
CN101271481B (en) Through-hole component auxiliary arranging system and method

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant
TR01 Transfer of patent right

Effective date of registration: 20180507

Address after: Room 04, 7 / F, Kay Road Development Tower, 33 Mong Kok Road, Kowloon, Hongkong, China

Patentee after: Fuyun Industrial Co., Ltd.

Address before: Taipei City, Taiwan, China

Patentee before: Inventec Corporation

TR01 Transfer of patent right
TR01 Transfer of patent right

Effective date of registration: 20180614

Address after: Su Yangshan street, Su Yang Shan town, Pizhou City, Xuzhou, Jiangsu

Patentee after: Pizhou Elson Electronic Technology Co., Ltd.

Address before: Room 04, 7 / F, Kay Road Development Tower, 33 Mong Kok Road, Kowloon, Hongkong, China

Patentee before: Fuyun Industrial Co., Ltd.

TR01 Transfer of patent right
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20090211

Termination date: 20190113

CF01 Termination of patent right due to non-payment of annual fee