* *** ** RF Wizard
Operation

**Operating
Gain Method**

**Available
Gain Method**

**Unilateral
Gain Method**

**Available
Gain Method**

Unilateral Gain Method

**
****Γ**** to ****Z Converter**

**
Series to****
Parallel
Transformer (Constant Q)**

** Impedance
Transformer**

** ****Impedance
Matcher**

**
****PAD Designer**

**
****MicroStrip Stub Designer**

**
BJT
Common-Emitter Amplifier Designer**

** J-FET
Common-Source Amplifier Designer**

**
MOSFET Common-Source Amplifier
Designer**

**CALCULATORS:**

** General-purpose Complex Number
Calculator**

** System
Noise and Intermodulation
Distortion Calculator**

** Bit
Error Rate vs Carrier-to-Noise
Ratio Calculator**

** Reactance
Calculator**

** Zo of MicroStrip
track**

** Width
of MicroStrip
track**

**1.
Stability**

**2.
Unilateral Figure of Merit Gain
Ratio **

**3.****
Operating Gain**

**4.****
Available Gain**

**5.****
Unilateral Gain
**

7.

**Introduction:**

**
RF Wizard **has
been created for
RF Designers, Educators, and Students to greatly simplify the normally
complex
tasks associated with

R.F. and Microwave Amplifier Design for specific gain and bandwidth. It also simplifies the design of matched interconnection networks

between R.F Sub-systems such as antennas, transmission lines, amplifiers, mixers, etc. Using Smith Charts and utilising a device’s Scattering

Parameter Data, in conjunction with a user-selected design methodology (

and Output Matching Design Solutions are arrived-at in

As its name suggests; the application provides a simple, step-by-step, “wizard” approach in order to simplify the design process.

Data can
be
input manually or from a Touchstone File.

Smith Chart Plots can be output to a printer

RF Wizard also includes 15 useful Calculators/Design Tools and
a number of
demonstration design process examples.

Data
input,
either Manual or from File, is initiated from the ** Matching
Designs**
drop-down menu on the opening form.

**Data
Input – File (Narrow Band Design Input):** **
**RF
Wizard accepts
input from Version 1 and 2, 2-Port, Touchstone Files, with the
Scattering
Parameter Data in Magnitude-Angle,

Decibel-Angle, or Real-Imaginary format. The data is converted to, and displayed in Magnitude-Angle format.

NOTE that
many S-data files do not adhere to the
Touchstone standard and therefore cause problems when being imported
into
the

RF Wizard Design Environment. These files can be created by
vector network
analyzers or circuit
analysis programs. Many can be

imported, but when the text contains subtle errors unexpected results
occur. To
repair these non-standard files, AWR has created a

utility **SdataConversion**** ( **__https://awrcorp.com/download/faq/english/questions/touchstone_file_repair.aspx__** )** which
can read
and carry

out several health checks and then repair the data.

An example
file access is shown below:

After the
file is read in, the following form
appears. The incoming Scattering Parameter data is tabled. In this
example, the
Touchstone File contained Noise

Data. This is tabled also. The S-Parameter data is plotted on the
accompanying
Smith Chart. Also plotted is a series of relevant Port1 and Port2
Stability

Arcs defining potential regions of instability over the device’s
frequency
range of operation. This is useful in ensuring that the selection Port1
or
Port2

impedances to set gain at a particular frequency can avoid possible
instability
(oscillation) at other frequencies.

In the
control panel of the figure above, note that the Port1 and Port2
Reference Impedances have been read in and because Narrow Band Design
has been

nominated, the Wide Band Design Panel is disabled.

In the figure below, preliminary data requirements are completed:

· Generator and Load Impedances are entered manually.

· A row of S-Parameter data at the frequency of interest is selected (left mouse-button).

·
If
designing for Low-Noise, the
corresponding row in the Noise Parameters Table

is also selected (left mouse-button), and the ** Incl.
Noise** radio
button is activated.

Press the**
Continue** button to move to
the Narrow Band Design phase:

__Back
to Contents__

**Data
Input – File
(Wide Band Design Input):** **
**In the
example below, a different file has been read in. S-Parameters
and
Stability Arcs have been plotted.
The

(

Press
the**
Continue** button to move to the Wide Band Design
phase:

**Narrow****
Band Design (Operating
Gain Method):**

With
the Operating
Gain Method, "selective mismatching" is applied in the Output
Network in order to achieve a required OVERALL GAIN while
conjugate

matching is simultaneously applied in the Input Network.

After data is input, either manually or from file, the form below appears:

In this (above), we see that the device is ** Unconditionally
Stable**, with
Rollett's Stability
Factor (

(Note: Had the device been assessed as

In this example, the

control panel.

The SMITH
CHART now appears (below), showing
five constant Operating Gain circles (concentric
around the point of
Maximum Operating Gain of

13.48 dB), along with the nominated Gammas. Note also, the text windows
which
provide continuous repeats of the mouse position on the chart

in terms of Reflection Coefficient ( Γ ), Impedance ( Z ), Q ( = X/R )
and Operating Gain ( Gp(dB)).

**(NOTE that Noise Figure values are displayed only for
Low-Noise designs
involving the Unilateral and Available Gain methods.)**

Note also
that
Input
and Output Stability Circles are **not** plotted for
values of
k greater
than
1.1
(here, k = 3.286).

Assume
that we wish to achieve an Overall Gain of 13dB.
Using the mouse, a **new***G*_{L}** _{ }**point is
selected and
plotted
on the 13dB circle (left button click),

and a

the program

This pair of points is assigned a plot number, and the details are listed to the right of the chart. More points can be plotted as required

Completion
of this phase of the design requires that you passively convert *G*_{L}** _{
}**to
the

**Narrow
Band
Design (Available
Gain Method):**

The SMITH
CHART reappears, (below)
showing the five required constant Available Gain circles
(concentric
around the point of Maximum

Available Gain of 20.13 dB), along with the nominated
Gammas.
The
“Gain Window” now continuously displays Available
Gain.

With the
Available Gain Method,
"selective mismatching" is applied in the Input Network, while
conjugate matching is simultaneously applied in

the Output Network in order to achieve a required overall gain.

Assume that we wish to achieve an Overall Gain of 20dB. A *new** **G*_{G}** **point is
selected and plotted on the 20dB circle, and a

corresponding

For each *new**G***_{G}** chosen
(for
a specific overall gain), the program

number, and the details are listed to the right of the chart. More points can be plotted as required.

As with the Operating Gain example, completion of this phase of the design requires that you passively convert

** Narrow
Band Design (Unilateral
Gain Method):**

In this example, a
new set of S-Parameters has been employed, such that the device
exhibits **Conditional
Stability*** *with *k* =
0.8 and regions of potential

instability defined by the Input and
Output Stability
Circles*.*

Upon accessing the
"Design Control" panel, then nominating assorted Gammas, the Smith
Chart (below) appears:

Note that
there are five Constant Input Gain
circles (blue) concentric around the point of Maximum Input Gain (G1)
of 1.94
dB (coincident with S_{11}*,

if plotted), and five Constant Output Gain circles (red)
concentric around
the point of Maximum Output Gain (G2) of 1.25 dB** **(coincident
with S_{22}*,

if plotted). Initially, the “Gain Window” displays Port1 gain
contribution
(blue) until selection, whereupon it switches to Port2 gain (red).

Assume a 19 dB overall gain requirement. The device itself provides
17.05 dB. The
requirement is met by allowing the input and
output circuits

to contribute the remaining 1.95 dB.

Using the Mouse's **Left and Right Buttons**
respectively, the points *new**G*_{G}** **(0.95 dB),
and *new**
**G*_{L}** _{ }** (1 dB) are
selected.

For
completion, passively convert *G*_{G}** **to the*
newG_{G}*

If manual
input is employed, Noise
Data must also be entered (below left).

The familiar "Design Control" panel again appears (above right).
Since a device's noise performance is a function of the **input
circuit**,
the Available

Gain and Unilateral Gain methods are the only viable choices.
For this
example, the ** Available
Gain Method** is nominated.

__Back
to Contents__

**Available****
Gain Method:**

The Smith Chart reappears (below) which, in addition to the Available
Gain
circles, includes a series of Constant Noise Figure circles (black)
concentric

around the Minimum Noise Figure value (here, 1.2 dB).

If, for
example, the design calls for an overall gain
of 19 dB at the lowest possible Noise Figure, then plot 1 (below) will
achieve
this (N.F. = 1.3 dB).

For completion, passively convert *G*_{G}** **to the

**Unilateral****
Gain Method:**

Alternatively, if employing the

If
we, as before, acquire a total of 2 dB from *G1* and *G2*,
we will
achieve an overall gain of 19 dB at a Noise Figure of approximately
1.35 dB
(below).

As before, for completion, passively convert *G*_{G}** **to the*
new *

This
design methodology is based on
the observation that for bandwidths that are short relative to the
overall
useful bandwidth of a high-frequency device, its

*S _{21}* characteristic variation
(and thus

be possible to independently adjust them at each end of the required bandwidth in order to flatten the overall response. (i.e.

The goal
of the following example is
a 19 dB **flat gain response** across a broad
bandwidth delineated by
the lower and upper frequencies: f_{1}= 2 GHz and f_{2}
= 3 GHz

respectively. The Input and Output networks will compensate
for the
expected 6 dB/octave gain roll-off in *|S _{21}*|.

The ** Unilateral
Design Method**
is employed.

The necessary Scattering Parameters at both frequencies are provided either manually, or from file.

Following
this, the “Wide Band Design
Select” form (below left) displays the Port1, Device and Port2,
Unilateral
Gains at both frequencies.

We can see
that the device itself (*Go*) undergoes
a 1.18 dB loss across the band. However, it appears
that this
shortfall can possibly be eliminated by

manipulation of the input and output circuits.
We
may also achieve an extra 2 dB or more, of overall
gain at both frequencies, to achieve the target of

19 dB. For
this to succeed, the constant *G1*
circles resulting from the gain adjustments (above right) **must
overlap **thus
providing TWO Generator

Impedances (one chosen) which fulfil the input gain requirements. The
same
discussion applies to the chosen*G2 *circles in the
output circuit for the

contributing output gain. See the figure below:

Note that
the chosen circles overlap asymmetrically
(necessary). If we are dissatisfied with the choice
of circles, we
can return to the previous panel,

and alter the plot parameters to generate new families of
circles for
consideration.

Consider the overlapping output circles (both 2.5 dB). We see that they are coincident at two points.

Now
consider the overlapping input circles (-0.53 and
0.65). We see that they are also
coincident
at two points. All that is required is to
select an input point

(mouse left-click) and a output point (mouse right-click)

Completion
of this phase of the design requires that
we passively convert *G*_{G}** **to the *new**G*_{G}**
**and

(again using the Impedance Transformer Tool).

With this method manufacturer-supplied, optimum, load-line-derived,
Output
Impedance data is input in either parallel (below left)

or equivalent-series form (below right).

"Continue"
results in the chart:

The chart
displays the **new***G*_{L}**_{ }**and the
computed

Completion
of
the design requires that we passively convert *G*_{G}** **to the *new**G*_{G}**
**and

(again using the Impedance Transformer Tool).

**
**

**
**

** **

**Impedance Transformer:**

For Input or Output gain-setting. Choose from L, Pi or T Networks

to transform a complex Z to a new Z (L-Transform shown below).

**Impedance Matcher:**

All combinations of L. Pi, and T for matching Z1 to Z2.

Shown below is a panel of Pi-Match Networks.

**PAD Designer:**

L, Pi, T, O, H, and Bridged-T, PAD networks are supported..

**MicroStrip Stub Designer:**

Short-Circuit, Open-Circuit and Resonant stubs from given Z0,

Track Width, Track Thickness, Dielectric Thickness, and D.K.

**BJT Common-Emitter Amplifier Designer:**

Six Common-Emitter circuit designs from given Vcc, Ic,

Beta/HFE, and frequency.

**J-FET Common-Source Amplifier Designer:**

**MOSFET Common-Source Amplifier Designer:**

__Back to Contents__

Calculators:

**· General-purpose
Complex Number Calculator:**

- Conversions:
Polar to Rectangular, Rectangular to Polar.
- Addition,
Subtraction, Multiplication and Division of Polar or Rectangular forms
of complex numbers

**System Noise and Intermodulation Distortion Calculator.**- System
Input 3rd-Order Intercept Point.
- System
Noise Figure.
- Thermal
Noise Floor.
- System
Noise Floor/Minimum Detectable Signal (MDS).
- Spurious-Free
Dynamic Range (SFDR).
- Plot of
results.

A number of “Design Select” panels/forms, pre-primed with data are provided to assist in familiarising the user in the design methods provided.

Each of
the Smith Chart forms has a ** Print
Chart** button in the lower right corner.

**1.****
STABILITY:
**The
device is considered to be
UNCONDITIONALLY STABLE if

Otherwise, stability will be CONDITIONAL upon the ( modified ) Generator and Load Gammas

( reflection coefficients) being situated outside the regions of instability, defined by the Input

and Output STABILITY CIRCLES (plotted on the Smith Charts).

**2.****
UNILATERAL FIGURE of MERIT GAIN RATIO (
U ): **Most
microwave
transistor amplifiers, are approximately Unilateral, that is, the
measured

S-Parameters satisfy |S12| << |S21|. To decide whether the 2-Port can be treated as

Unilateral, a "Unilateral Figure of Merit Gain Ratio" is used, which is essentially a comparison of

the Unilateral Gain to the Bilateral Gain under the same input and output matching conditions.

**3.****
OPERATING GAIN:
**Operating
Gain is
defined as the ratio of the POWER OUT OF THE NETWORK to the

POWER INTO THE NETWORK, i.e.,

by varying

values of power gain.

**4.****
AVAILABLE GAIN:
**Available
Gain is
defined as the ratio of the MAXIMUM POWER OUT to the MAXIMUM

POWER IN, i.e.,

simultaneously varying the Load End,

**5.****
UNILATERAL GAIN:
**A
unilateral device
has, by definition S12
= 0. Under this condition, a 2-Port
network

can be broken into THREE sources of gain;

itself,

by the output circuit. Thus

**6.
MAXIMUM
AVAILABLE GAIN (MAG):
Gain
is maximised when the
two-port is simultaneously conjugate matched ( G_{IN
}=
G_{G}*
and
G_{OUT
}=
G_{L}*).
The
necessary and sufficient condition for simultaneous matching is K
≥ 1,
where K is the Rollett
Stability
Factor.**

**7.
MAXIMUM STABLE GAIN (MSG):****
**This
is the MAXIMUM value MAG can have, which is
achievable when

instability.