Multipath wireless solutions: The RAKE receiver

Multipath in wireless systems is what happens when a transmitted signal travels along multiple paths ( e.g. as a result of reflections from surfaces). At the receiver these received signals can add or subtract depending on the amplitude and phase of the signals causing what is known as frequency selective fading. Another name for multipath interference. Obviously this is a real problem for cellular systems and many different types of solutions have been proposed and are being used. One of these solutions is the so-called RAKE receiver. The RAKE receiver has a number of “sub-receivers” called fingers, each assigned to a different multipath component. Each finger independently receives a single multipath signal. Subsequently, the contribution of all fingers are combined in order to make the most use of the different transmission characteristics of each transmission path. The important parameters that need to be estimated as accurately as possible are, the time of arrival of each finger signal, its amplitude and phase. Knowing these, the signals are combined in what is known as a maximal ratio combiner or a MRC. In this combiner each individual finger signal is weighted by the complex valued channel gain. The effect of this weighting is to compensate for the phase shifts in the channel and the change in amplitude. As this is done successfully significant improvement in signal reception is obtained. For details on a RAKE receiver design please contact Signal Processing Group Inc., through the website located at http://www.signalpro.biz.

LNA

SPG designs, develops and delivers custom analog and RF/wireless asics and modules.

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

A wideband RF detector

A wideband RF detector

Linear detector performance

Linear detector performance curves

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: spg@signalpro.biz 24/7

Wideband RF detector perforamce , more details

Contact Signal Processing Group Inc.

Please contact Signal Processing Group Inc. on email: spg@signalpro.biz . 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: spg@signalpro.biz 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.
General operation.
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: spg@signalpro.biz 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

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 spg@signalpro.biz for more information

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