Smith Chart Marker Formats

When using the Smith chart display, markers can show impedance data in 13 different formats. Select the format that best suits your measurement needs.

Change Marker Format

1. Set a trace to Smith chart format
2. Tap the screen to open the menu
3. Navigate to MARKER > SMITH FORMAT
4. Select the desired format

Available Formats

Basic Formats

Format	Display	Description
LIN	Linear	Linear reflection coefficient magnitude
LOG	Log dB	Reflection coefficient in dB
Re/Im	r + ji	Complex reflection coefficient
R+jX	R + jX ohms	Impedance in rectangular form

Component Formats

Format	Display	Description
R+L/C	R + L or C	Resistance plus series inductance or capacitance
G+B	G + jB	Conductance and susceptance
G+L/C	G + L or C	Conductance plus parallel L or C

Parallel Equivalent Formats

Format	Display	Description
Rp+Xp	Rp + jXp	Parallel equivalent impedance
Rp+L/C	Rp + L/C	Parallel R with L or C

Shunt Equivalent Formats

Format	Display	Description
R+jX(sh)	R + jX (shunt)	Shunt equivalent series impedance
R+L/C(sh)	R + L/C (shunt)	Shunt equivalent with component value

Series Equivalent Formats

Format	Display	Description
R+jX(ser)	R + jX (series)	Series equivalent impedance
R+L/C(ser)	R + L/C (series)	Series equivalent with component value

Format Details

R+jX (Rectangular Impedance)

The most common format showing resistance and reactance:

Z = R + jX ohms

Where:

• R = Resistance (real part)
• X = Reactance (imaginary part, positive = inductive, negative = capacitive)

R+L/C (Component Values)

Shows resistance plus the equivalent component value:

Z = 50 + j31.4 ohms  -->  50 ohms + 10 nH @ 500 MHz

The firmware calculates the component value from reactance at the marker frequency.

Tip

Use R+L/C format when you need to know what component value would match the measured impedance.

G+B (Admittance)

Shows conductance and susceptance (inverse of impedance):

Y = G + jB siemens

Useful for parallel circuit analysis and matching network design.

Parallel Equivalent (Rp+Xp)

Converts the impedance to parallel equivalent form:

Series: Rs + jXs  -->  Parallel: Rp || jXp

Useful when designing parallel resonant circuits or matching networks.

Shunt/Series Equivalent

For two-port measurements, shows the equivalent impedance in shunt or series configuration.

Shell Commands

Set Smith marker format via serial console:

# Set Smith marker format for a trace
trace {0|1|2|3} {format}

# Smith formats:
# lin|log|ri|rx|rlc|gb|glc|rpxp|rplc|rxsh|rlcsh|rxser|rlcser

# Examples:
trace 0 smith rx      # R+jX format
trace 0 smith rlc     # R + L/C format
trace 0 smith gb      # G + jB format
trace 0 smith rpxp    # Parallel Rp + jXp

Practical Applications

Antenna Impedance Analysis

Use R+jX format to see resistance and reactance directly:

1. Set trace to Smith chart
2. Set marker format to R+jX
3. Place marker at resonance
4. Read impedance directly

Matching Network Design

Use R+L/C format for direct component values:

1. Measure the load impedance
2. Set format to R+L/C
3. The displayed L or C value indicates what component would resonate out the reactance

Crystal Measurement

Use R+jX with series/shunt formats:

1. Connect crystal in series or shunt fixture
2. Select appropriate series or shunt format
3. Read motional parameters directly

Choosing the Right Format

Application	Recommended Format
General impedance	R+jX
Component matching	R+L/C
Parallel circuits	Rp+L/C or G+L/C
Matching networks	R+jX or G+B
RF amplifier design	G+B
Filter design	R+L/C

Caution

Component values (L/C) are only valid at the marker frequency. The actual component may have different values at other frequencies due to parasitics.