INSTRUCTIONS FOR USING CMX940 PHASE NOISE CALCULATOR

Disclaimer: This calculator is a free tool provided by CML Microcircuits (UK) Limited; it is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

The program is run in Octave 5.1.0.0 (later versions may also work but they have not been tested) which can be downloaded for free from https://www.octave.org/download.html.

All files required to run the program are contained in the folder "CMX940_Loop_Noise_Calculator". This folder must be saved to your computer.

How to use the program:
Either:
	Open the application "Octave-5.1.0.0 (GUI)" (or relevant downloaded version).
	Set the current directory (on the toolbar in the top left of the screen) to the "CMX940_Loop_Noise_Calculator" folder.
	Type "CMX940_LNC_1" into the Command Window and then press enter.
Or:
	Open the command prompt application.
	Set the directory to the "CMX940_Loop_Noise_Calculator" folder by using the change directory command (for example: cd C:\Users\"name"\Documents\CMX940_Loop_Noise_Calculator ) then press enter.
	Type "CMX940_LNC_1" into the Command Prompt and then press enter.

You will then be propted to choose a UI size: small, standard or large. The size of the small UI is 35.5 cm x 17.5 cm, the size of the standard UI is 42.5 cm x 20.5 cm and the size of the large UI is 50.5 cm x 24 cm. The default is standard size.
This will run the program and the UI will pop-up.
The UI has various parts with different functions.

NOTE:	When the UI is dragged from a computer screen to a monitor screen and back it is possible that this will affect the UI dimensions. To return to the default UI the program must be opened from the Octave command window/prompt again.

When the UI opens it will start by showing the "Parameter Settings" tab. This contains all of the input values required to run the program. A set of default values are initially displayed and these can be changed by clicking on the relevant boxes and editting the values as required.

The "Graphical Plots" box allows the user to tick all of the options they would like to plot.

The "Lines shown in Loop Noise Plot" box allows the user to select which lines they would like to see in the "Loop Noise" plot. This allows the user to consider individual components more easily and 'de-clutter' their graphs if neccasary.

The "Graph Frequency Limits" box allows the user to choose the scale on the frequency axis.

The "Main Values" box allows the user to choose all of the specific values required for the simulator including the Capacitance, Resistance, Frequency and Division values as well as the noise profiles of the Reference Oscillator and the Voltage Controlled Oscilator.

The "VCO Tuning Slope Settings" box allows the user to choose between their manually inputted Tuning Constant value and an automatically calculated value. The CMX940 has two VCOs so when the automatic setting is selected the user must select which one they'd like. Finally the user can select "Automatic Switching" to be on or off. If this is on the simulator will switch VCOs if the VCO frequency is not in the correct band for the selected VCO and will revert to the manual setting if the VCO frequency is outside VCO frequency bands. If this setting is turned off the simulator will not change any of the inputted settings.

The "Tick Components to Reset" box allows the user to reset components to their default values. This is done by ticking the components the user wants to reset and then pressing the "Reset Selected Components" button. This will reset the selected components and untick the boxes.

The "Load Input Data" button allows the user to choose different default data from various save slots. To do this, click on the "Load Input Data" button and a pop-out box appears. The user can either load data from a numbered save slot (Default, 1-20) or a custom save slot which is a name specified by the user. To do this the user must select the relevant numbered save slot from the drop down box or type the name of the custom save slot into the editable box. Then the user must select the relevant load button and this will load the saved values into the UI and also save these values in the "Tick Components to Reset" box.

The "Save Input Data" button allows the user to save the current input data into various save slots. To do this, click on the "Save Input Data" button and a pop-out box appears. The user can either save data into a numbered save slot (1-20) or a custom save slot which is a name specified by the user. To do this the user must select the relevant numbered save slot from the drop down box or type the name of the custom save slot into the editable box. Then the user must select the relevant save button and this will save the input values into the selected save slot.

The "Resize Text" button allows the user to adjust the size of the text (in terms of the size measurement 'point') displayed on the UI - not including table text. To do this, click on the "Resize Text" box and a pop-out box appears. Adjust the slider and then press the "Resize Text" button. This will adjust the size of the text in the UI and the value is updated in the "Resize Text Box". To return the original value select the "Reset Text Size" button.

The "Resize Tables" button allows the user to adjust the size of the text (in terms of the size measurement 'point') and the column widths (in terms of a scale factor) of the various tables on the UI. To do this, click on the "Resize Tables" box and a pop-out box appears. Adjust the relevant slider and press the corresponding button below, either "Resize Table Text" or "Rescale Column Width". This will adjust these setting in the UI and the value is updated in the "Resize Tables Box". To return to the original values select the relevant button, either "Reset Table Text" or "Reset Column Width".

Click on the "CMX940 Block Diagram" tab to see a block diagram of the circuit board. The user can click on the component buttons to change their values. This will also update the relevant values in the "Parameter Settings" tab.

Click on the "Loop Filter Diagram" tab to see a diagram of the resistor-capacitor network which forms the Loop Filter. There are five buttons in this diagram that can be used to change the relevant Capacitance and Resistance values. This will also update the relevant values in the "Parameter Settings" tab.

Click on the "Noise Profiles" tab to see how the noise generated by the Reference Oscillator and the Voltage Controlled Oscillator is plotted; there are four buttons in this diagram that can be used to change the relevant input values. This will also update the relevant values in the "Parameter Settings" tab.

Click on the "Analysis" tab to in order to caluclate the recommended Capacitance, Resistance, Frequency and Division values for the simulation. On the left hand side of the tab we can calculate the Capactiance and Resistance values, as well as the bandwidth. To do this we first input two 'new' values: the Natural Frequency and the Damping Factor as well as four values from the "Parameter Settings" tab. We can then calculate our required values and then further specify the Capacitance and Resistance values in the E3, E6, E12 or E24 series form. We then have an option to set all the non-zero values as our values in the "Parameter Settings" tab. On the right hand side we calculate the frequency and division values. We can once again recall the current values from the "Parameter Settings" tab and then set any value we want to calculate either to 0 or leave it blank. The calculator will then compute the frequency and division values, if it calculates multiple values for a component it will come up with an error telling the user which component had multiple values. It may also not calculate all the values, in this case it will warn the user that there were not enough inputs. Finally we can input all the non-zero values in the "Parameter Settings" tab.

Click on the "Spur Avoidance" tab in order to calculate where spurs may occur in the noise profile. In order to do this we need a number of input values. 'Reference Frequency', 'REFPLL M DIV Value', 'SYN_SDIV Value' and 'Output Divider' value are all user inputs to the CMX940. The 'SPLL Bandwidth' multiplied by the 'Spur Finding Factor' controls the range in which the calculator looks for spurs relative to the centre frequency. The starting, stopping and step frequency control which output frequencies are analysed. The user also has an option to plot graphs of the VCO spurs and the Output spurs, the user can tick or untick the boxes to show the graphs. When the 'Calculate Spurs' button is pressed a table is produced detailing all the calculated integer, half, third, quarter and fifth spurs, the graphs are also generated at this point. This data can then be saved to a text file and a csv file by pressing the 'Save Spur Table'. There are also 'Load Settings' and 'Save Settings' buttons for the Spur Avoidance inputs. All of these buttons work in the same way as the load/save buttons in the "Parameter Settings" tab.

Click on the "Run Calculator" tab to plot the graphs the user has selected in the "Graphical Plots" box. The plots will be made in a pop-out figurewhich will include a marker which will include information about the plot at various frequencies. The marker can be moved, reset or hidden by using the "Marker Settings Box" which is also created when the "Run Calculator" tab is selected. The plots will overlay so if the user wants a fresh figure the original figure must be closed and then a new figure will be created when the "Run Calculator" tab is next pressed.