What causes a circuit to be unbalanced?

Discussion in 'Wireless & RF Design' started by Bradcay, Jan 5, 2016.

  1. Bradcay

    Thread Starter New Member

    Jan 5, 2016
    I've been reading about balanced and unbalanced antenna circuits.

    I'm wondering, is an alternate path to ground the only thing that can make a circuit unbalanced?
  2. Papabravo


    Feb 24, 2006
    Not exactly. It is true that RF travels on the surface of a conductor to a depth which is a function of frequency. Ladder line is balanced because the conductors are parallel and the currents flow in opposite directions. Coaxial cable on the other hand, has an inner and outer surface to the shield. Currents can and do flow on both surfaces, but depending on the frequency and the magnitudes of the currents may appear either almost balanced or unbalanced.
    Bradcay likes this.
  3. fiberstorejames

    New Member

    Aug 5, 2014
    Unbalanced circuitis one in which the transmission properties between the ports of the circuit are different for the two poles of each port. It is usually taken to mean that one pole of each port is bonded to a common potential (single-ended signalling) but more complex topologies are possible.To complete any type of circuits, including audio circuits, you must have two wires (or signal paths). Signals flow from one piece of equipment to another via these two wires. Unbalanced is utilizing one active wire and one ground/shield wire return for a single audio feed. The audio is impressed on the one active or hot wire. Nearly all audio inputs require the active wire to be shielded. That is, the ground is braided or spirally wound around the active (hot) wire.
  4. BR-549

    Well-Known Member

    Sep 22, 2013
    In a balanced circuit, the signal references itself. In an unbalanced circuit, the signals references to something external.