  The magnetar Swift J1834.9-0846 is observed using Nanshan 25 meter radio
telescope. No pulsed radio emission is detected. The upper limit on pulsed
radio emission from this source is 0.5 mJy. According to the fundamental plane
for radio magnetars, this source should have radio emission. Therefore, our
results put constraints on the existence of a fundamental plane of magnetar
radio emission. We argue that a magnetar's ability to emit radio emission may
have little to do with the spin down luminosity and it is related to the
magnetar X-ray luminosity. The only necessary condition is a relatively low
X-ray luminosity.
