Interference between circuit components

Hi,

If I have to design a circuit working on few GHz, consist of less than 10 components (capacitor/inductor/resistor/diode)
My first question is, is it better to place the components next to each other like this, or make some calculated transmission lines between them like this? which will make me change some of the components value I think!
In other words, is the interfere among the components considerable or not, or depend on the component type, like inductor more than the resistor?

the second question (which is related to the same issue), is it reasonable to place a mixer with these components on the same board, or place it on an other separate board?

Thanks

Second picture, some traces are designed to be inductive, so that is why components are placed apart. RFI is no problem as long as it is a single stage one a PCB. Problems start when ground loops are shared between mixers, digital circuits, LNA and such. In schoolbook you can find examples on how to keep high isolation by dividing ground-plane in different isles depending on type of circuit but for complex circuits is it often hard to do. Assume that you have two high gain amplifiers in serial in GHz range on same PCB. Even if everything is very well designed can it be complicated to achieve high enough isolation, avoiding unwanted feedback resulting in worst case in self oscillation.
Avoid reflections due to poor designed transmission lines and avoid that ground loops share same area. Divide different parts of the circuit with shield cans can also improve isolation and reduce RFI problems in both directions, as each circuit both is a source and a victim for unwanted signals. That is why some circuits have a shield can divided in several sub sections.
If a circuit is well designed is it seldom any need to separate different functions on separate PCB. Separated PCB's increase problem with handling transmission losses and reflections. Designing for shortest possible traces results in less problem due to impedance mismatch. Do not forget that Vcc is also a common signal path which can feed signal backward resulting in all kinds of problems. Decoupling Vcc with shortest possible traces to ground is the general rule but in some cases can both inductors and resistors or ferrite beads be needed to avoid unwanted feedback.

very good points again..
thanks so much for your reply