Discussion with VHF 2-way radio (marine transceiver)

[surfing]

156mhz vhf receiver schematic

please find the attached tech. document of one 2-way radio from Kenwood, model of TK-8150. just for your reference.
Recently i was charging of developing the similar the 2-way radio, I want to get your help here.
any comments and suggestion is appreciated.

firstly, i want to ensure the following issues:
1. Receiver: for the Intermodulation spec. . which parts is most critical? LNA, mixer, or IF?
anyone can build up one block diagram in ADS to simulate the nonlinearity performance?
2. other specification of receiver: Spurious response, and blocking..

Anyway, I will bring up more tech. question here, let me understand more detail in these traditional FM radio. Thanks much for your help

 

[surfing]

marine vhf transceiver block diagram

the attached documents is "service manual" of this 2-way radio, including schematic, PCB layout, part list etc.
it's a good example to let us to discuss the 2-way radio in about 156MHz VHF band

 

[surfing]

vhf intermodulation marine

How to evaluate the "intermod. rejection" and "blocking/desensitization" in FM super-hereodyne receiver?
anyone give some comments?

 

[kspalla]

Is it custom requirement or a standard. I mean you need to verify for the compliance against any standard?
In general the standard will give the test method too.
Go through the document word by word.
Hope you will get the clue.

 

[surfing]

thanks for ur reply.

all the test and measurement, including certification standard, i fully understand.

what i am interested, is that I can simulate these parameter in system design.

for example, I can simulate the "intermodulation rejection" of this type of 2-downconverter FM receiver in agilent ADS system design.
to emulate which component have more cricital effect in system, LNA, mixer or filter?

can anyone give me such example or suggestion to me in simulation in ADS.

my project is oooooooooooold FM receiver. I cannot find examples in ADS example, where too many of modern communication, GSM, CDMA...

 

[kspalla]

IMDs are due to non-linearities in the amplifier.
If the incoming signal exceeds the rated input then you will observe the IMDs (which will be lower under low power of operation.)

FFPA is the technique for reducing the IMDs generated by the amplifier with higher efficiency.
Its a complex circuit so I suggest to find the linear device and operate under lower efficiency.

Share the zipped ADS project if possible to understand

 

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