The Spacing Circle in double stub matching
In double stub matching the two stubs are spaced a predetermined distance away from each other. These distances are typically λ/8, λ/4, 3λ/8, 5λ/8 etc. Knowing what we know about a length of line acting as a transformer, we know that the length of line between the two stubs acts as a transformer. The action of this transformer is to convert the admittance at the position of stub 2 to a different admittance at the position of stub 1. So we start from the position of stub 2.
In order that stub 2 can be finally used to match the line admittance, the real part of the admittance at the position of stub 2, on the line, has to be 1.0 (normalized value). Its susceptance is then jB. jB is the susceptance that is cancelled using stub 2 to ultimately get the matching to the line admittance. The admittance at the position of stub 2, (without the stub) lies on the constant conductance, g = 1 circle. The admittances on the g = 1 circle are all the possible admittances at the stub 2 position for a match to take place.
To reiterate, as a result of these deliberations, that some point of the VSWR circle formed by the position of stub 2, must intersect the g=1 or the unity conductance circle on the Smith Chart.
We also conclude, that the admittance at the position of the first stub, must lie on
a circle of equal radius but having its center rotated (moved to or displaced) by the spacing between the stubs towards the load. Lets call this spacing ‘d’.
This circle is called the spacing circle.
Please visit our website for more articles of interest.
FPGA Design and development service
Contact SPG using phone: 602-626-0272 for fast service.
A wideand RF detector ( 40 Mhz to 3 Ghz) -75 dBm to 5 dBm input
Linear detector performance
A wideband linear RF detector
Price for one unit: $25.00. Lead time for delivery 3 days. 30 Day return policy. Pricing for 100 units or more: $20.00 per unit. Please contact Signal Processing Group Inc. for details for purchase from Signal Processing Group Inc. Email: firstname.lastname@example.org 24/7
Wideband RF detector perforamce , more details
Contact Signal Processing Group Inc.
Please contact Signal Processing Group Inc. on email: email@example.com . We will answer within 24 hours.
2 stage 35 dB gain RF amplifier. Front of the module
Full range frequency response
2 stage amplifier deta
Please see details at http://www.signalpro.biz/2rf_amplifier_details.htm Delivery lead time is 3 days. Return within 30 days for a full refund. Price is $15.00 for one unit and $10.00 per unit in volumes of 100. For higher volumes than 100 please contact Signal Processing group Inc.
miniature LNA module
Mni LNA performance
Delivery lead time is 3 days. Return within 30 days for a full refund. Price is $15.00 for one unit and $12.00 per unit in volumes of 100. For higher volumes than 100 please contact Signal Processing Group Inc. at email: firstname.lastname@example.org or call 602-626-0272 for fastest service.
A high frequency divider from 500 Mhz to % Ghz+
The input interface.
The frequency divider has a differential analog interface. The following parameters apply:
The minimum frequency that can be input is 500 Mhz and the maximum frequency is 6.0 Ghz.
The RF input level is 5 dBm to – 5 dBm. For lower frequencies make sure that the slew rate is
greater than 560 V/us. The input is biased by two 500 Ohm resistors connected to a 1.6V DC bias.
Therefore AC coupling is used at the input. These are two 100pF capacitors.
The output interface.
The output is single ended. The output driver is capable of sourcing and sinking 24 mA. The
equivalent output impedance is 50 Ohm. To avoid reflections it is recommended that the divider
work into a 50 Ohm load.
The inputs are applied to the input SMA I/O. The product will work with both a differential input as
well as a single ended input. However, a differential input works best. The division ratio is applied
to the N1 and N2 control inputs as follows:
N2 N1 Division ratio
0 0 8
0 1 16
1 0 32
1 1 64
The logic levels are:
Logic level Voltage
1 1.4V minimum
0 0.6V maximum
The supply voltage interface.
The operating supply voltage is 3.3V typical. The quiescent (DC) operating supply current is 2 mA.
A high frequency divider 500 Mhz to 5 Ghz+
Contact Signal Processing Group Inc for details and acquisition
Please contact Signal Processing Group Inc. at email: email@example.com or telephone 602-626-0272. Get a response within minutes or worst case 24 hours if contact is by email.
SPDT DC to 3 Ghz RF switch
DC to 3 Ghz RF SPDT switch
RF Switch typical features
Supply voltage = Vcc = 0/+5 Vdc
Operatng temperature = TA = -50° C to 125 Deg C
Operating impedance = 50 Ohm
Input power for 1 dB
compression ( 5.0V system) = 37 dBm ( f = 0.5 to 3 Ghz)
Input third order Intercept = 64 dBm ( 0 to 5.0V system, f = 0.5 to 3 Ghz)
Operating frequency range = DC to 3 Ghz.
Insertion loss DC to 3 Ghz = 0.8 dB
Isolation DC to 3 Ghz = 14 dB minimum
Return loss DC to 3 Ghz = 20 dB
50% contl to 10/90 %
( ON/OFF) = 120 ns
A single stage RF amplifier as a gain block
A single stage RF amplifier summary specifications
Gain, Operating: 19.5 dB
Operating frequency range: 1.0 – 2700 Mhz
OIP3: (Pout = 19.0 dBm), -8.5 dBm
P1dB: 4.6 dBm
N.F: 4.2 dB
Supply voltage Operating: 3.3 – 5.5 Volts
Price: single unit $7.50, 100 units : $5:50.
Free delivery, shipping lead time 2 days.
30 day return policy, buyer ships.
Supply current Supply = 5.0V, 23.0 mA
Embedded design and development
Signal Processing Group Inc. is offering embedded design and development using Microchip processors. Please contact us on firstname.lastname@example.org for more information